The cassandra.yaml configuration file

The cassandra.yaml file is the main configuration file for Cassandra.

Important: After changing properties in the cassandra.yaml file, you must restart the node for the changes to take effect. It is located in the following directories:

Cassandra package installations: /etc/cassandra
Cassandra tarball installations: install_location/conf

The configuration properties are grouped into the following sections:

Quick start
The minimal properties needed for configuring a cluster.
Commonly used
Properties most frequently used when configuring Cassandra.
Performance tuning
Tuning performance and system resource utilization, including commit log, compaction, memory, disk I/O, CPU, reads, and writes.
Advanced
Properties for advanced users or properties that are less commonly used.
Security
Server and client security settings.

Note: Values with ^note mark default values that are defined internally, missing, or commented out, or whose implementation depends on other properties in the cassandra.yaml file. Additionally, some commented-out values may not match the actual default values. These are recommended alternatives to the default values.

Quick start properties

The minimal properties needed for configuring a cluster.

cluster_name: (Default: Test Cluster) The name of the cluster. This setting prevents nodes in one logical cluster from joining another. All nodes in a cluster must have the same value.

listen_address

(Default: localhost) The IP address or hostname that Cassandra binds to for connecting this node to other nodes. Set this parameter or listen_interface, not both. Correct settings for various use cases:

Single-node installations: do one of the following:
- Comment this property out. If the node is properly configured (host name, name resolution, and so on.), Cassandra uses InetAddress.getLocalHost() to get the local address from the system.
- Leave set to the default, localhost.
Node in a multi-node installations: set this property to the node's IP address or hostname, or set listen_interface.
Node in a multi-network or multi-Datacenter installation, within an EC2 environment that supports automatic switching between public and private interfaces: set listen_address to the node's IP address or hostname, or set listen_interface.
Node with two physical network interfaces in a multi-datacenter installation or a Cassandra cluster deployed across multiple Amazon EC2 regions using the Ec2MultiRegionSnitch:
1. Set listen_address to this node's private IP or hostname, or set listen_interface (for communication within the local datacenter).
2. Set broadcast_address to the second IP or hostname (for communication between datacenters).
3. Set listen_on_broadcast_address to true.
4. If this node is a seed node, add the node's public IP address or hostname to the seeds list.
Open the storage_port or ssl_storage_port on the public IP firewall.

Warning:

Never set listen_address to 0.0.0.0. It is always wrong.
Do not set values for both listen_address and listen_interface on the same node.

listen_interface: (Default: eth0)^note The interface that Cassandra binds to for connecting to other Cassandra nodes. Interfaces must correspond to a single address — IP aliasing is not supported. Do not set values for both listen_address and listen_interface on the same node.

listen_interface_prefer_ipv6: (Default: false) If an interface has an ipv4 and an ipv6 address, Cassandra uses the first ipv4 address by default. Set this property to true to configure Cassandra to use the first ipv6 address.

Default directories

If you have changed any of the default directories during installation, set these properties to the new locations. Make sure you have root access.

cdc_raw_directory

The directory where the CDC log is stored. Default locations:

Package installations: /var/lib/cassandra/cdc_raw
Tarball installations: install_location/data/cdc_raw

The directory where Change Data Capture logs are stored.

Directories for the CDC logs and the commit logs must reside in the same filesystem.

commitlog_directory

The directory where the commit log is stored. Default locations:

Package installations: /var/lib/cassandra/commitlog
Tarball installations: install_location/data/commitlog

For optimal write performance, place the commit log be on a separate disk partition, or (ideally) a separate physical device from the data file directories. Because the commit log is append only, an HDD is acceptable for this purpose.

Directories for the commit logs and the CDC logs must reside in the same filesystem.

data_file_directories

The directory location where table data is stored (in SSTables). Cassandra distributes data evenly across the location, subject to the granularity of the configured compaction strategy. Default locations:

Package installations: /var/lib/cassandra/data
Tarball installations: install_location/data/data

As a production best practice, use RAID 0 and SSDs.

saved_caches_directory

The directory location where table key and row caches are stored. Default location:

Package installations: /var/lib/cassandra/saved_caches
Tarball installations: install_location/data/saved_caches

Commonly used properties

Properties most frequently used when configuring Cassandra.

Before starting a node for the first time, you should carefully evaluate your requirements.

Common initialization properties

Note: Be sure to set the properties in the Quick start section as well.

commit_failure_policy

(Default: stop) Policy for commit disk failures:

die
Shut down gossip and Thrift and kill the JVM, so the node can be replaced.
stop
Shut down gossip and Thrift, leaving the node effectively dead, available for inspection using JMX.
stop_commit
Shut down the commit log, letting writes collect but continuing to service reads (as in pre-2.0.5 Cassandra).
ignore
Ignore fatal errors and let the batches fail.

disk_optimization_strategy: (Default: ssd) The strategy for optimizing disk reads. Possible values: ssd or spinning.

disk_failure_policy

(Default: stop) Sets how Cassandra responds to disk failure. Recommend settings: stop or best_effort. Valid values:

die
Shut down gossip and Thrift and kill the JVM for any file system errors or single SSTable errors, so the node can be replaced.
stop_paranoid
Shut down gossip and Thrift even for single SSTable errors.
stop
Shut down gossip and Thrift, leaving the node effectively dead, but available for inspection using JMX.
best_effort
Stop using the failed disk and respond to requests based on the remaining available SSTables. This allows obsolete data at consistency level of ONE.
ignore
Ignore fatal errors and lets the requests fail; all file system errors are logged but otherwise ignored. Cassandra acts as in versions prior to 1.2.

endpoint_snitch

(Default: org.apache.cassandra.locator.SimpleSnitch) Set to a class that implements the IEndpointSnitch interface. Cassandra uses the snitch to locate nodes and route requests.

SimpleSnitch
Use for single-datacenter deployment or single-zone deployment in public clouds. Does not recognize datacenter or rack information. Treats strategy order as proximity, which can improve cache locality when you disable read repair.
GossipingPropertyFileSnitch
Recommended for production. Reads rack and datacenter for the local node in cassandra-rackdc.properties file and propagates these values to other nodes via gossip. For migration from the PropertyFileSnitch, uses the cassandra-topology.properties file if it is present.
The location of the cassandra-rackdc.properties file depends on the type of installation:
Package installations /etc/cassandra/cassandra-rackdc.properties
Tarball installations install_location/conf/cassandra-rackdc.properties

The location of the cassandra-topology.properties file depends on the type of installation:
Package installations /etc/cassandra/cassandra-topology.properties
Tarball installations install_location/conf/cassandra-topology.properties
PropertyFileSnitch
Determines proximity by rack and datacenter, which are explicitly configured in cassandra-topology.properties file.
Ec2Snitch
For EC2 deployments in a single region. Loads region and availability zone information from the Amazon EC2 API. The region is treated as the datacenter and the availability zone as the rack and uses only private IP addresses. For this reason, it does not work across multiple regions.
Ec2MultiRegionSnitch
Uses the public IP as the broadcast_address to allow cross-region connectivity. This means you must also set seed addresses to the public IP and open the storage_port or ssl_storage_port on the public IP firewall. For intra-region traffic, Cassandra switches to the private IP after establishing a connection.
RackInferringSnitch:
Proximity is determined by rack and datacenter, which are assumed to correspond to the 3rd and 2nd octet of each node's IP address, respectively. Best used as an example for writing a custom snitch class (unless this happens to match your deployment conventions).
GoogleCloudSnitch:
Use for Cassandra deployments on Google Cloud Platform across one or more regions. The region is treated as a datacenter and the availability zones are treated as racks within the datacenter. All communication occurs over private IP addresses within the same logical network.
CloudstackSnitch
Use the CloudstackSnitch for Apache Cloudstack environments.

Related information: Snitches

rpc_address

(Default: localhost) The listen address for client connections (Thrift RPC service and native transport). Valid values:

unset:
Resolves the address using the configured hostname configuration of the node. If left unset, the hostname resolves to the IP address of this node using /etc/hostname, /etc/hosts, or DNS.
0.0.0.0:
Listens on all configured interfaces. You must set the broadcast_rpc_address to a value other than 0.0.0.0.
IP address
hostname

Related information: Network

rpc_interface: (Default: eth1)^note The listen address for client connections. Interface must correspond to a single address, IP aliasing is not supported. See rpc_address.

rpc_interface_prefer_ipv6: (Default: false) If an interface has an ipv4 and an ipv6 address, Cassandra uses the first ipv4 address by default, i. If set to true, the first ipv6 address will be used.

seed_provider

The addresses of hosts designated as contact points in the cluster. A joining node contacts one of the nodes in the -seeds list to learn the topology of the ring.

class_name (Default: org.apache.cassandra.locator.SimpleSeedProvider)
The class within Cassandra that handles the seed logic. It can be customized, but this is typically not required.
- seeds (Default: 127.0.0.1)
A comma-delimited list of IP addresses used by gossip for bootstrapping new nodes joining a cluster. If your cluster includes multiple nodes, you must change the list from the default value to the IP address of one of the nodes.
Attention: In multiple data-center clusters, include at least one node from each datacenter (replication group) in the seed list. Designating more than a single seed node per datacenter is recommended for fault tolerance. Otherwise, gossip has to communicate with another datacenter when bootstrapping a node.
Making every node a seed node is not recommended because of increased maintenance and reduced gossip performance. Gossip optimization is not critical, but it is recommended to use a small seed list (approximately three nodes per datacenter).

enable_user_defined_functions: (Default: false) User defined functions (UDFs) present a security risk, since they are executed on the server side. In Cassandra 3.0 and later, UDFs are executed in a sandbox to contain the execution of malicious code. They are disabled by default.

enable_scripted_user_defined_functions: (Default: false) Java UDFs are always enabled, if enable_user_defined_functions is true. Enable this option to use UDFs with language javascript or any custom JSR-223 provider. This option has no effect if enable_user_defined_functions is false.

Common compaction settings

compaction_throughput_mb_per_sec: (Default: 16) Throttles compaction to the specified Mb/second across the instance. The faster Cassandra inserts data, the faster the system must compact in order to keep the SSTable count down. The recommended value is 16 to 32 times the rate of write throughput (in Mb/second). Setting the value to 0 disables compaction throttling.
Related information: Configuring compaction

compaction_large_partition_warning_threshold_mb: (Default: 100) Cassandra logs a warning when compacting partitions larger than the set value.

Common memtable settings

memtable_heap_space_in_mb: (Default: 1/4 of heap size)^note; The amount of on-heap memory allocated for memtables. Cassandra uses the total of this amount and the value of memtable_offheap_space_in_mb to set a threshold for automatic memtable flush. For details, see memtable_cleanup_threshold.
Related information: Tuning the Java heap

memtable_offheap_space_in_mb: (Default: 1/4 of heap size)^note; Sets the total amount of off-heap memory allocated for memtables. Cassandra uses the total of this amount and the value of memtable_heap_space_in_mb to set a threshold for automatic memtable flush. For details, see memtable_cleanup_threshold.
Related information: Tuning the Java heap

Common disk settings

concurrent_reads: (Default: 32)^note Workloads with more data than can fit in memory encounter a bottleneck in fetching data from disk during reads. Setting concurrent_reads to (16 × number_of_drives) allows operations to queue low enough in the stack so that the OS and drives can reorder them. The default setting applies to both logical volume managed (LVM) and RAID drives.

concurrent_writes: (Default: 32)^note Writes in Cassandra are rarely I/O bound, so the ideal number of concurrent writes depends on the number of CPU cores on the node. The recommended value is 8 × number_of_cpu_cores.

concurrent_counter_writes: (Default: 32)^note Counter writes read the current values before incrementing and writing them back. The recommended value is (16 × number_of_drives) .

concurrent_batchlog_writes: (Default: 32) Limit on the number of concurrent batchlog writes, similar to concurrent_writes.

concurrent_materialized_view_writes: (Default: 32) Limit on the number of concurrent materialized view writes. Set this to the lesser of concurrent reads or concurrent writes, because there is a read involved in each materialized view write.

Common automatic backup settings

incremental_backups: (Default: false) Backs up data updated since the last snapshot was taken. When enabled, Cassandra creates a hard link to each SSTable flushed or streamed locally in a backups subdirectory of the keyspace data. Removing these links is the operator's responsibility.
Related information: Enabling incremental backups

snapshot_before_compaction: (Default: false) Enables or disables taking a snapshot before each compaction. A snapshot is useful to back up data when there is a data format change. Be careful using this option: Cassandra does not clean up older snapshots automatically.
Related information: Configuring compaction

Common fault detection setting

phi_convict_threshold: (Default: 8)^note Adjusts the sensitivity of the failure detector on an exponential scale. Generally this setting does not need adjusting.
Related information: Failure detection and recovery

Performance tuning properties

Tuning performance and system resource utilization, including commit log, compaction, memory, disk I/O, CPU, reads, and writes.

Commit log settings

commitlog_sync

(Default: periodic) The method that Cassandra uses to acknowledge writes in milliseconds:

periodic: (Default: 10000 milliseconds [10 seconds])
With commitlog_sync_period_in_ms, controls how often the commit log is synchronized to disk. Periodic syncs are acknowledged immediately.
batch: (Default: disabled)^note
With commitlog_sync_batch_window_in_ms (Default: 2 ms), controls how long Cassandra waits for other writes before performing a sync. When this method is enabled, Cassandra does not acknowledge writes until they are fsynced to disk.

commitlog_segment_size_in_mb

(Default: 32MB) The size of an individual commitlog file segment. A commitlog segment may be archived, deleted, or recycled after all its data has been flushed to SSTables. This data can potentially include commitlog segments from every table in the system. The default size is usually suitable for most commitlog archiving, but if you want a finer granularity, 8 or 16 MB is reasonable.

By default, the max_mutation_size_in_kb is set to half of the commitlog_segment_size_in_kb.

Related information: Commit log archive configuration

max_mutation_size_in_kb

(Default: ½ of commitlog_segment_size_in_mb.

If a mutation's size exceeds this value, the mutation is rejected. Before increasing the commitlog segment size of the commitlog segments, investigate why the mutations are larger than expected. Look for underlying issues with access patterns and data model, because increasing the commitlog segment size is a limited fix.

Restriction:

If you set max_mutation_size_in_kb explicitly, then you must set commitlog_segment_size_in_mb to at least twice the size of max_mutation_size_in_kb / 1024.

For more information, see commitlog_segment_size_in_mb above.

commitlog_compression: (Default: not enabled) The compressor to use if commit log is compressed. Valid values: LZ4, Snappy or Deflate. If no value is set for this property, the commit log is written uncompressed.

cdc_total_space_in_mb: (Default: 4096MB and 1/8thof the total space of the drive where the cdc_raw_directory resides.)^note If space gets above this value, Cassandra will throw WriteTimeoutException on Mutations including tables with CDC enabled. A CDCCompactor (a consumer) is responsible for parsing the raw CDC logs and deleting them when parsing is completed.

cdc_free_space_check_interval_ms: (Default: 250 ms)^note When the cdc_raw limit is hit and the CDCCompactor is either running behind or experiencing backpressure, this interval is checked to see if any new space for cdc-tracked tables has been made available.

commitlog_total_space_in_mb: (Default: 32MB for 32-bit JVMs, 8192MB for 64-bit JVMs)^note Total space used for commit logs. If the total space used by all commit logs goes above this value, Cassandra rounds up to the next nearest segment multiple and flushes memtables to disk for the oldest commitlog segments, removing those log segments from the commit log. This reduces the amount of data to replay on start-up, and prevents infrequently-updated tables from keeping commitlog segments indefinitely. If the commitlog_total_space_in_mb is small, the result is more flush activity on less-active tables.
Related information: Configuring memtable thresholds

Compaction settings

Related information: Configuring compaction

concurrent_compactors: (Default: Smaller of number of disks or number of cores, with a minimum of 2 and a maximum of 8 per CPU core)^noteThe number of concurrent compaction processes allowed to run simultaneously on a node, not including validation compactions for anti-entropy repair. Simultaneous compactions help preserve read performance in a mixed read-write workload by limiting the number of small SSTables that accumulate during a single long-running compaction. If your data directories are backed by SSDs, increase this value to the number of cores. If compaction running too slowly or too fast, adjust compaction_throughput_mb_per_sec first.
Note: Increasing concurrent compactors leads to more use of available disk space for compaction, because concurrent compactions happen in parallel, especially for STCS. Ensure that adequate disk space is available before increasing this configuration.

sstable_preemptive_open_interval_in_mb: (Default: 50MB) The compaction process opens SSTables before they are completely written and uses them in place of the prior SSTables for any range previously written. This setting helps to smoothly transfer reads between the SSTables by reducing page cache churn and keeps hot rows hot.

Memtable settings

memtable_allocation_type: (Default: heap_buffers) The method Cassandra uses to allocate and manage memtable memory. See Off-heap memtables in Cassandra 2.1. In releases 3.2.0 and 3.2.1, the only option that works is: heap-buffers (On heap NIO (non-blocking I/O) buffers).

memtable_cleanup_threshold

(Default: 1/(memtable_flush_writers + 1))^note. Ratio used for automatic memtable flush. Cassandra adds memtable_heap_space_in_mb to memtable_offheap_space_in_mb and multiplies the total by memtable_cleanup_threshold to get a space amount in MB. When the total amount of memory used by all non-flushing memtables exceeds this amount, Cassandra flushes the largest memtable to disk.

For example, consider a node where the total of memtable_heap_space_in_mb and memtable_offheap_space_in_mb is 1000, and memtable_cleanup_threshold is 0.50. The memtable_cleanup amount is 500MB. This node has two memtables: Memtable A (150MB) and Memtable B (350MB). When either memtable increases, the total space they use exceeds 500MB and Cassandra flushes the Memtable B to disk.

A larger value for memtable_cleanup_threshold means larger flushes, less frequent flushes and potentially less compaction activity, but also less concurrent flush activity, which can make it difficult to keep your disks saturated under heavy write load.

This section documents the formula used to calculate the ratio based on the number of memtable_flush_writers. The default value in cassandra.yaml is 0.11, which works if the node has many disks or if you set the node's memtable_flush_writers to 8. As another example, if the node uses a single SSD, the value for memttable_cleanup_threshold computes to 0.33, based on the minimum memtable_flush_writers value of 2.

file_cache_size_in_mb: (Default: Smaller of 1/4 heap or 512) Total memory to use for SSTable-reading buffers.

buffer_pool_use_heap_if_exhausted: (Default: true)^note Indicates whether Cassandra allocates allocate on-heap or off-heap memory when the SSTable buffer pool is exhausted (when the buffer pool has exceeded the maximum memory file_cache_size_in_mb), beyond this amount, Cassandra stops caching buffers, but allocates on request.

memtable_flush_writers: (Default: Smaller of number of disks or number of cores with a minimum of 2 and a maximum of 8)^note The number of memtable flush writer threads. These threads are blocked by disk I/O, and each one holds a memtable in memory while blocked. If your data directories are backed by SSDs, increase this setting to the number of cores.

Cache and index settings

column_index_size_in_kb: (Default: 64) Granularity of the index of rows within a partition. For huge rows, decrease this setting to improve seek time. If you use key cache, be careful not to make this setting too large because key cache will be overwhelmed. If you're unsure of the size of the rows, it's best to use the default setting.

index_summary_capacity_in_mb: (Default: 5% of the heap size [empty])^note Fixed memory pool size in MB for SSTable index summaries. If the memory usage of all index summaries exceeds this limit, any SSTables with low read rates shrink their index summaries to meet this limit. This is a best-effort process. In extreme conditions, Cassandra may use more than this amount of memory.

index_summary_resize_interval_in_minutes: (Default: 60 minutes) How frequently index summaries should be re-sampled. Re-sampling is done periodically to redistribute memory from the fixed-size pool to SSTables proportional their recent read rates. To disable, set to -1. This setting leaves existing index summaries at their current sampling level.

Disks settings

stream_throughput_outbound_megabits_per_sec: (Default: 200 Mbps)^note Throttle for the throughput of all outbound streaming file transfers on a node. Cassandra does mostly sequential I/O when streaming data during bootstrap or repair. This can saturate the network connection and degrade client (RPC) performance.

inter_dc_stream_throughput_outbound_megabits_per_sec: (Default: unset)^note Throttle for all streaming file transfers between datacenters, and for network stream traffic as configured with stream_throughput_outbound_megabits_per_sec.

trickle_fsync: (Default: false) When set to true, causes fsync to force the operating system to flush the dirty buffers at the set interval trickle_fsync_interval_in_kb. Enable this parameter to prevent sudden dirty buffer flushing from impacting read latencies. Recommended for use with SSDs, but not with HDDs.

trickle_fsync_interval_in_kb: (Default: 10240). The size of the fsync in kilobytes.

windows_timer_interval: (Default: 1) The default Windows kernel timer and scheduling resolution is 15.6ms for power conservation. Lowering this value on Windows can provide much tighter latency and better throughput. However, some virtualized environments may see a negative performance impact from changing this setting below the system default. The sysinternals clockres tool can confirm your system's default setting.

Advanced properties

Properties for advanced users or properties that are less commonly used.

Advanced initialization properties

auto_bootstrap: (Default: true) This setting has been removed from default configuration. It causes new (non-seed) nodes migrate the right data to themselves automatically. When initializing a fresh cluster without data, add auto_bootstrap: false.
Related information: Initializing a multiple node cluster (single datacenter) and Initializing a multiple node cluster (multiple datacenters).

batch_size_warn_threshold_in_kb: (Default: 5KB per batch) Causes Cassandra to log a WARN message when any batch size exceeds this value in kilobytes.
CAUTION: Increasing this threshold can lead to node instability.

batch_size_fail_threshold_in_kb: (Default: 50KB per batch) Cassandra fails any batch whose size exceeds this setting. The default value is 10X the value of batch_size_warn_threshold_in_kb.

unlogged_batch_across_partitions_warn_threshold: (Default: 10partitions per batch) Causes Cassandra to log a WARN message on any batches not of type LOGGED that span across more partitions than this limit. The default value is 10 partitions.

cdc_enabled: (Default: commented out) Enable / disable CDC functionality on a per-node basis. This modifies the logic used for write path allocation rejection (standard: never reject. cdc: reject Mutation containing a CDC-enabled table if at space limit in cdc_raw_directory).
Important: Do not enable CDC on a mixed-version cluster. Upgrade all nodes to Cassandra 3.8 before enabling and restarting the cluster.

broadcast_address: (Default: listen_address)^note The "public" IP address this node uses to broadcast to other nodes outside the network or across regions in multiple-region EC2 deployments. If this property is commented out, the node uses the same IP address or hostname as listen_address. A node does not need a separate broadcast_address in a single-node or single-datacenter installation, or in an EC2-based network that supports automatic switching between private and public communication. It is necessary to set a separate listen_address and broadcast_address on a node with multiple physical network interfaces or other topologies where not all nodes have access to other nodes by their private IP addresses. For specific configurations, see the instructions for listen_address.

listen_on_broadcast_address

(Default: false) If this node uses multiple physical network interfaces, set a unique IP address for broadcast_address and set listen_on_broadcast_address to true. This enables the node to communicate on both interfaces.

Set this property to false if the node is on a network that automatically routes between public and private networks, as Amazon EC2 does.

For configuration details, see the instructions for listen_address.

initial_token: (Default: disabled) Set this property for single-node-per-token architecture, in which a node owns exactly one contiguous range in the ring space. Setting this property overrides num_tokens.; If your Cassandra installation is not using vnodes or this node's num_tokens is set it to 1 or is commented out, you should always set an initial_token value when setting up a production cluster for the first time, and when adding capacity. For more information, see this parameter in the Cassandra 1.1 Node and Cluster Configuration documentation.; This parameter can be used with num_tokens (vnodes ) in special cases such as Restoring from a snapshot.

num_tokens: (Default: 256) ^note The number of tokens randomly assigned to this node in a cluster that uses virtual nodes (vnodes). This setting is evaluated in relation to the num_tokens set on other nodes in the cluster. If this node's num_tokens value is higher than the values on other nodes, the vnode logic assigns this node a larger proportion of data relative to other nodes. In general, if all nodes have equal hardware capability, each one should have the same num_tokens value . The recommended value is 256. If this property is commented out (#num_tokens), Cassandra uses 1 (equivalent to #num_tokens : 1) for legacy compatibility and assigns tokens using the initial_token property.; If this cluster is not using vnodes, comment out num_tokens or set num_tokens: 1 and use initial_token. If you already have an existing cluster with one token per node and wish to migrate to vnodes, see Enabling virtual nodes on an existing production cluster.

allocate_tokens_keyspace: (Default: KEYSPACE) Enables automatic allocation of num_tokens tokens for this node. The allocation algorithm attempts to choose tokens in a way that optimizes replicated load over the nodes in the datacenter for the replication strategy used by the specified KEYSPACE. The load assigned to each node will near proportional to its number of vnodes.

partitioner

(Default: org.apache.cassandra.dht.Murmur3Partitioner) Sets the class that distributes rows (by partition key) across all nodes in the cluster. Any IPartitioner may be used, including your own as long as it is in the class path. For new clusters use the default partitioner.

Cassandra provides the following partitioners for backwards compatibility:

RandomPartitioner
ByteOrderedPartitioner (deprecated)
OrderPreservingPartitioner (deprecated)

Related information: Partitioners

storage_port: (Default: 7000) The port for inter-node communication.

tracetype_query_ttl: (Default: 86400) TTL for different trace types used during logging of the query process

tracetype_repair_ttl: (Default: 604800) TTL for different trace types used during logging of the repair process.

Advanced automatic backup setting

auto_snapshot: (Default: true) Enables or disables whether Cassandra takes a snapshot of the data before truncating a keyspace or dropping a table. To prevent data loss, Datastax strongly advises using the default setting. If you set auto_snapshot to false, you lose data on truncation or drop.

Key caches and global row properties

When creating or modifying tables, you can enable or disable the key cache (partition key cache) or row cache for that table by setting the caching parameter. Other row and key cache tuning and configuration options are set at the global (node) level. Cassandra uses these settings to automatically distribute memory for each table on the node based on the overall workload and specific table usage. You can also configure the save periods for these caches globally.

Related information: Configuring caches

key_cache_keys_to_save: (Default: disabled - all keys are saved)^note Number of keys from the key cache to save.

key_cache_save_period: (Default: 14400 seconds [4 hours]) Duration in seconds that keys are kept in cache. Caches are saved to saved_caches_directory. Saved caches greatly improve cold-start speeds and have relatively little effect on I/O.

key_cache_size_in_mb: (Default: empty) A global cache setting for the maximum size of the key cache in memory (for all tables). If no value is set, the cache is set to the smaller of 5% of the available heap, or 100MB. To disable set to 0.
Related information: setcachecapacity, Enabling and configuring caching.

column_index_cache_size_in_kb: (Default: 2) A threshold for the total size of all index entries for a partition that Cassandra stores in the partition key cache. If the total size of all index entries for a partition exceeds this amount, Cassandra stops putting entries for this partition into the partition key cache. This limitation prevents index entries from large partitions from taking up all the space in the partition key cache (which is controlled by key_cache_size_in_mb).

row_cache_class_name: (Default: disabled - row cache is not enabled)^note The classname of the row cache provider to use. Valid values: OHCProvider (fully off-heap) or SerializingCacheProvider (partially off-heap).

row_cache_keys_to_save: (Default: disabled - all keys are saved)^note Number of keys from the row cache to save.

row_cache_size_in_mb: (Default: 0- disabled) Maximum size of the row cache in memory. The row cache can save more time than key_cache_size_in_mb,, but it is space-intensive because it contains the entire row. Use the row cache only for hot rows or static rows. If you reduce the size, you may not get you hottest keys loaded on start up.

row_cache_save_period: (Default: 0- disabled) The number of seconds that rows are kept in cache. Caches are saved to saved_caches_directory. This setting has limited use as described in row_cache_size_in_mb.

Counter caches properties

Counter cache helps to reduce counter locks' contention for hot counter cells. In case of RF = 1 a counter cache hit causes Cassandra to skip the read before write entirely. With RF > 1 a counter cache hit still helps to reduce the duration of the lock hold, helping with hot counter cell updates, but does not allow skipping the read entirely. Only the local (clock, count) tuple of a counter cell is kept in memory, not the whole counter, so it is relatively cheap.

Note: If you reduce the counter cache size, Cassandra may load the hottest keys start-up.

counter_cache_size_in_mb: (Default value: empty)^note When no value is set, Cassandra uses the smaller of minimum of 2.5% of Heap or 50MB. If your system performs counter deletes and relies on low gc_grace_seconds, you should disable the counter cache. To disable, set to 0.

counter_cache_save_period: (Default: 7200 seconds [2 hours]) the amount of time after which Cassandra saves the counter cache (keys only). Cassandra saves caches to saved_caches_directory.

counter_cache_keys_to_save: (Default value: disabled)^note Number of keys from the counter cache to save. When this property is disabled, Cassandra saves all keys.

Tombstone settings

When executing a scan, within or across a partition, Cassandra must keep tombstones in memory to allow them to return to the coordinator. The coordinator uses tombstones to ensure that other replicas know about the deleted rows. Workloads that generate numerous tombstones may cause performance problems and exhaust the server heap. See Cassandra anti-patterns: Queues and queue-like datasets. Adjust these thresholds only if you understand the impact and want to scan more tombstones. You can adjust these thresholds at runtime using the StorageServiceMBean.

tombstone_warn_threshold: (Default: 1000) Cassandra issues a warning if a query scans more than this number of tombstones.

tombstone_failure_threshold: (Default: 100000) Cassandra aborts a query if it scans more than this number of tombstones.

Network timeout settings

range_request_timeout_in_ms: (Default: 10000 milliseconds) The number of milliseconds that the coordinator waits for sequential or index scans to complete before timing it out.

read_request_timeout_in_ms: (Default: 5000 milliseconds) The number of milliseconds that the coordinator waits for read operations to complete before timing it out.

counter_write_request_timeout_in_ms: (Default: 5000 milliseconds) The number of milliseconds that the coordinator waits for counter writes to complete before timing it out.

cas_contention_timeout_in_ms: (Default: 1000 milliseconds) The number of milliseconds during which the coordinator continues to retry a CAS (compare and set) operation that contends with other proposals for the same row. If the coordinator cannot complete the operation within this timespan, it aborts the operation.

cqlTruncateequest_timeout_in_ms: (Default: 60000 milliseconds) The number of milliseconds that the coordinator waits for a truncate (the removal of all data from a table) to complete before timing it out. The long default value allows Cassandra to take a snapshot before removing the data. If auto_snapshot is disabled (not recommended), you can reduce this time.

write_request_timeout_in_ms: (Default: 2000 milliseconds) The number of milliseconds that the coordinator waits for a write operations to complete before timing it out.
Related information: Hinted Handoff: repair during write path

request_timeout_in_ms: (Default: 10000 milliseconds) The default timeout value for other miscellaneous operations.
Related information: Hinted Handoff: repair during write path

Inter-node settings

cross_node_timeout: (Default: false) Enables or disables operation timeout information exchange between nodes (to accurately measure request timeouts). If this property is disabled, Cassandra assumes the requests are forwarded to the replica instantly by the coordinator, which means that under overload conditions extra time is required for processing already-timed-out requests.
CAUTION: Before enabling this property make sure NTP (network time protocol) is installed and the times are synchronized among the nodes.

internode_send_buff_size_in_bytes

(Default: N/A)^note The sending socket buffer size in bytes for inter-node calls.

The buffer size set by this parameter and internode_recv_buff_size_in_bytes is limited by net.core.wmem_max. If this property is not set, net.ipv4.tcp_wmem determines the buffer size. See man tcp and:

/proc/sys/net/core/wmem_max
/proc/sys/net/core/rmem_max
/proc/sys/net/ipv4/tcp_wmem
/proc/sys/net/ipv4/tcp_wmem

Related information: TCP settings

internode_recv_buff_size_in_bytes: (Default: N/A)^noteThe receiving socket buffer size in bytes for inter-node calls.

internode_compression

(Default: all) Controls whether traffic between nodes is compressed. Valid values:

all
Compresses all traffic.
dc
Compresses traffic between datacenters only.
none
No compression.

inter_dc_tcp_nodelay: (Default: false) Enable this property or disable tcp_nodelay for inter-datacenter communication. If this property is disabled, the network sends larger, but fewer, network packets. This reduces overhead from the TCP protocol itself. However, disabling inter_dc_tcp_nodelay may increase latency by blocking cross data-center responses.

streaming_socket_timeout_in_ms: (Default: 3600000 - 1 hour)^note Enables or disables socket timeout for streaming operations. If a streaming times out by exceeding this number of milliseconds, Cassandra retries it from the start of the current file. Setting this value too low can result in a significant amount of data re-streaming.

Native transport (CQL Binary Protocol)

start_native_transport: (Default: true) Enables or disables the native transport server. This server uses the same address as the rpc_address, but the port it uses is different from rpc_port. See native_transport_port.

native_transport_port: (Default: 9042) The port where the CQL native transport listens for clients.

native_transport_max_threads

(Default: 128)^note The maximum number of thread handling requests. Similar to rpc_max_threads, but this property differs as follows:

The default for native_transport_max_threads is 128; the default for rpc_max_threads is unlimited.
There is no corresponding native_transport_min_threads.
Cassandra stops idle native transport threads after 30 seconds.

native_transport_max_frame_size_in_mb: (Default: 256MB) The maximum allowed size of a frame. Frame (requests) larger than this are rejected as invalid.

native_transport_max_concurrent_connections: (Default: -1) The maximum number of concurrent client connections. The default value of -1 means unlimited.

native_transport_max_concurrent_connections_per_ip: (Default: -1) The maximum number of concurrent client connections per source IP address. The default value of -1 means unlimited.

RPC (remote procedure call) settings

Settings for configuring and tuning client connections.

broadcast_rpc_address: (Default: unset)^note The RPC address for broadcast to drivers and other Cassandra nodes. This cannot be set to 0.0.0.0. If left blank, Cassandra uses the rpc_address or rpc_interface. If rpc_address or rpc_interfaceis set to 0.0.0.0, this property must be set.

rpc_port: (Default: 9160) Thrift port for client connections.

start_rpc: (Default: true) Enables or disables the Thrift RPC server.

rpc_keepalive: (Default: true) Enables or disables keepalive on client connections (RPC or native).

rpc_max_threads: (Default: unlimited)^note Regardless of your choice of RPC server (rpc_server_type), rpc_max_threads dictates the maximum number of concurrent requests in the RPC thread pool. If you are using the parameter sync (see rpc_server_type) it also dictates the number of clients that can be connected. A high number of client connections could cause excessive memory usage for the thread stack. Connection pooling on the client side is highly recommended. Setting a rpc_max_threads acts as a safeguard against misbehaving clients. If the number of threads reaches the maximum, Cassandra blocks additional connections until a client disconnects.

rpc_min_threads: (Default: 16)^noteThe minimum thread pool size for remote procedure calls.

rpc_recv_buff_size_in_bytes: (Default: N/A)^note The receiving socket buffer size for remote procedure calls.

rpc_send_buff_size_in_bytes: (Default: N/A)^note The sending socket buffer size in bytes for remote procedure calls.

rpc_server_type

(Default: sync) Cassandra provides three options for the RPC server. On Windows, sync is about 30% slower than hsha. On Linux, sync and hsha performance is about the same, but hsha uses less memory.

sync: (Default: one thread per Thrift connection.)
For a very large number of clients, memory is the limiting factor. On a 64-bit JVM, 180KB is the minimum stack size per thread and corresponds to your use of virtual memory. Physical memory may be limited depending on use of stack space.
hsha:
Half synchronous, half asynchronous. All Thrift clients are handled asynchronously using a small number of threads that does not vary with the number of clients. This mechanism scales well to many clients. The RPC requests are synchronous (one thread per active request).
Note: If you select this option, you must change the default value (unlimited) of rpc_max_threads.
Your own RPC server
You must provide a fully-qualified class name of an o.a.c.t.TServerFactory that can create a server instance.

Advanced fault detection settings

Settings to handle poorly performing or failing components.

gc_warn_threshold_in_ms: (Default: 1000) Any GC pause longer than this interval is logged at the WARN level. (By default, Cassandra logs any GC pause greater than 200 ms at the INFO level.)
Additional information: Configuring logging.

dynamic_snitch_badness_threshold: (Default: 0.1) The performance threshold for dynamically routing client requests away from a poorly performing node. Specifically, it controls how much worse a poorly performing node has to be before the dynamic snitch prefers other replicas over it. A value of 0.2 means Cassandra continues to prefer the static snitch values until the node response time is 20% worse than the best performing node. Until the threshold is reached, incoming requests are statically routed to the closest replica (as determined by the snitch). A value greater than zero for this parameter, with a value of less than 1.0 for read_repair_chance, maximizes cache capacity across the nodes.

dynamic_snitch_reset_interval_in_ms: (Default: 600000 milliseconds) Time interval after which Cassandra resets all node scores. This allows a bad node to recover.

dynamic_snitch_update_interval_in_ms: (Default: 100 milliseconds) The number of milliseconds between Cassandra's calculation of node scores. Because score calculation is CPU intensive, be careful when reducing this interval.

hints_flush_period_in_ms: (Default: 10000) The number of milliseconds Cassandra waits before flushing hints from internal buffers to disk.

hints_directory: (Default: $CASSANDRA_HOME/data/hints) The directory in which hints are stored.

hinted_handoff_enabled: (Default: true) Enables or disables hinted handoff. To enable per datacenter, add a list of datacenters. For example: hinted_handoff_enabled: DC1,DC2. A hint indicates that the write needs to be replayed to an unavailable node. Cassandra writes the hint to a hints file on the coordinator node.
Related information: Hinted Handoff: repair during write path

hinted_handoff_disabled_datacenters: (Default: none) A blacklist of datacenters that will not perform hinted handoffs. To disable hinted handoff on a certain datacenter, , add its name to this list. For example: hinted_handoff_disabled_datacenters: - DC1 - DC2.
Related information: Hinted Handoff: repair during write path

hinted_handoff_throttle_in_kb: (Default: 1024) Maximum amount of traffic per delivery thread in kilobytes per second. This rate reduces proportionally to the number of nodes in the cluster. For example, if there are two nodes in the cluster, each delivery thread uses the maximum rate. If there are three, each node throttles to half of the maximum, since the two nodes are expected to deliver hints simultaneously.
Note: When applying this limit, Cassandra computes the hint transmission rate based on the uncompressed hint size, even if internode_compression or hints_compression is enabled.

max_hint_window_in_ms: (Default: 10800000 milliseconds [3 hours]) Maximum amount of time during which Cassandra generates hints for an unresponsive node. After this interval, Cassandra does not generate any new hints for the node until it is back up and responsive. If the node goes down again, Cassandra starts a new interval. This setting can prevent a sudden demand for resources when a node is brought back online and the rest of the cluster attempts to replay a large volume of hinted writes.
Related information: Failure detection and recovery

max_hints_delivery_threads: (Default: 2) Number of threads Cassandra uses to deliver hints. In multiple data-center deployments, consider increasing this number because cross data-center handoff is generally slower.

max_hints_file_size_in_mb: (Default: 128) The maximum size for a single hints file, in megabytes.

hints_compression: (Default: LZ4Compressor) The compressor for hint files. Supported compressors: LZ, Snappy, and Deflate. If you do not specify a compressor, Cassandra does not compress hints files.

batchlog_replay_throttle_in_kb: (Default: 1024KB per second) Total maximum throttle for replaying hints. Throttling is reduced proportionally to the number of nodes in the cluster.

Request scheduler properties

Settings to handle incoming client requests according to a defined policy. If your nodes are overloaded and dropping requests, DataStax recommends that you add more nodes rather than use these properties to prioritize requests.

Note: The properties in this section apply only to the Thrift transport. They have no effect on the use of CQL over the native protocol.

request_scheduler

(Default: org.apache.cassandra.scheduler.NoScheduler) The scheduler to handle incoming client requests according to a defined policy. This scheduler is useful for throttling client requests in single clusters containing multiple keyspaces. This parameter is specifically for requests from the client and does not affect inter-node communication. Valid values:

org.apache.cassandra.scheduler.NoScheduler
Cassandra does no scheduling.
org.apache.cassandra.scheduler.RoundRobinScheduler
Cassandra uses a round robin of client requests to a node with a separate queue for each request_scheduler_id property.
Cassandra uses a Java class that implements the RequestScheduler interface.

request_scheduler_id: (Default: keyspace)^note The scope of the scheduler's activity. Currently the only valid value is keyspace. See weights.

request_scheduler_options

(Default: disabled) A list of properties that define configuration options for request_scheduler:

throttle_limit: The number of in-flight requests per client. Requests beyond this limit are queued up until running requests complete. Recommended value is ((concurrent_reads + concurrent_writes) × 2).
default_weight: (Default: 1)^note
How many requests the scheduler handles during each turn of the RoundRobin.
weights: (Default: Keyspace: 1)
A list of keyspaces. How many requests the scheduler handles during each turn of the RoundRobin, based on the request_scheduler_id.

Thrift interface properties

Legacy API for older clients. CQL is a simpler and better API for Cassandra.

thrift_framed_transport_size_in_mb: (Default: 15) Frame size (maximum field length) for Thrift. The frame is the row or part of the row that the application is inserting.

thrift_max_message_length_in_mb: (Default: 16) The maximum length of a Thrift message in megabytes, including all fields and internal Thrift overhead (1 byte of overhead for each frame). Calculate message length in conjunction with batches. A frame length greater than or equal to 24 accommodates a batch with four inserts, each of which is 24 bytes. The required message length is greater than or equal to 24+24+24+24+4 (number of frames).

Security properties

Server and client security settings.

authenticator

(Default: AllowAllAuthenticator) The authentication backend. It implements IAuthenticator for identifying users. Available authenticators:

AllowAllAuthenticator:
Disables authentication; Cassandra performs no checks.
PasswordAuthenticator
Authenticates users with user names and hashed passwords stored in the system_auth.credentials table. Leaving the default replication factor of 1 set for the system_auth keyspace results in denial of access to the cluster if the single replica of the keyspace goes down. For multiple datacenters, be sure to set the replication class to NetworkTopologyStrategy.

Related information: About Internal authentication

internode_authenticator: (Default: enabled)^note Internode authentication backend. It implements org.apache.cassandra.auth.AllowAllInternodeAuthenticator to allows or disallow connections from peer nodes.

authorizer

(Default: AllowAllAuthorizer) The authorization backend. It implements IAuthenticator to limit access and provide permissions. Available authorizers:

AllowAllAuthorizer
Disables authorization: Cassandra allows any action to any user.
CassandraAuthorizer
Stores permissions in system_auth.permissions table. Leaving the default replication factor of 1 set for the system_auth keyspace results in denial of access to the cluster if the single replica of the keyspace goes down. For multiple datacenters, be sure to set the replication class to NetworkTopologyStrategy.

Related information: Object permissions

role_manager: (Default: CassandraRoleManager) Part of the Authentication & Authorization backend that implements IRoleManager to maintain grants and memberships between roles. Out of the box, Cassandra provides org.apache.cassandra.auth.CassandraRoleManager, which stores role information in the system_auth keyspace. Most functions of the IRoleManager require an authenticated login, so unless the configured IAuthenticator actually implements authentication, most of this functionality will be unavailable. CassandraRoleManager stores role data in the system_auth keyspace. If you use the role manager, increase system_auth keyspace replication factor .

roles_validity_in_ms: (Default: 2000) Fetching permissions can be an expensive operation depending on the authorizer, so this setting allows flexibility. Validity period for roles cache; set to 0 to disable. Granted roles are cached for authenticated sessions in AuthenticatedUser and after the period specified here, become eligible for (async) reload. Disabled automatically for AllowAllAuthenticator.

roles_update_interval_in_ms: (Default: 2000) Enable to refresh interval for roles cache. Defaults to the same value as roles_validity_in_ms. After this interval, cache entries become eligible for refresh. Upon next access, Cassandra schedules an async reload, and returns the old value until the reload completes. If roles_validity_in_ms is non-zero, then this must be also.

credentials_validity_in_ms: (Default: 2000) How many milliseconds credentials in the cache remain valid. This cache is tightly coupled to the provided PasswordAuthenticator implementation of IAuthenticator. If another IAuthenticator implementation is configured, Cassandra does not use this cache, and these settings have no effect. Set to 0 to disable.
Related information: Internal authentication, Internal authorization
Note: Credentials are cached in encrypted form. This may cause a performance penalty that offsets the reduction in latency gained by caching.

credentials_update_interval_in_ms: (Default: same value as credentials_validity_in_ms) After this interval, cache entries become eligible for refresh. The next time the cache is accessed, the system schedules an asynchronous reload of the cache. Until this cache reload is complete, the cache returns the old values.
If credentials_validity_in_ms is nonzero, this property must also be nonzero.

permissions_validity_in_ms: (Default: 2000) How many milliseconds permissions in cache remain valid. Depending on the authorizer, such as CassandraAuthorizer, fetching permissions can be resource intensive. This setting is disabled when set to 0 or when AllowAllAuthorizer is set.
Related information: Object permissions

permissions_update_interval_in_ms: (Default: same value as permissions_validity_in_ms)^note If enabled, sets refresh interval for the permissions cache. After this interval, cache entries become eligible for refresh. On next access, Cassandra schedules an async reload and returns the old value until the reload completes. If permissions_validity_in_ms is nonzero, roles_update_interval_in_ms must also be non-zero.

server_encryption_options

Enables or disables inter-node encryption. If you enable server_encryption_options, you must also generate keys and provide the appropriate key and truststore locations and passwords. There are no custom encryption options currently enabled for Cassandra. Available options:

internode_encryption: (Default: none) Enables or disables encryption of inter-node communication using the TLS_RSA_WITH_AES_128_CBC_SHA cipher suite for authentication, key exchange, and encryption of data transfers. Use the DHE/ECDHE ciphers, such as TLS_DHE_RSA_WITH_AES_128_CBC_SHA if running in (Federal Information Processing Standard) FIPS 140 compliant mode. Available inter-node options:
- all
  Encrypt all inter-node communications.
- none
  No encryption.
- dc
  Encrypt the traffic between the datacenters (server only).
- rack
  Encrypt the traffic between the racks (server only).
keystore: (Default: conf/.keystore)
The location of a Java keystore (JKS) suitable for use with Java Secure Socket Extension (JSSE), which is the Java version of the Secure Sockets Layer (SSL), and Transport Layer Security (TLS) protocols. The keystore contains the private key used to encrypt outgoing messages.
keystore_password: (Default: cassandra)
Password for the keystore.
truststore: (Default: conf/.truststore)
Location of the truststore containing the trusted certificate for authenticating remote servers.
truststore_password: (Default: cassandra)
Password for the truststore.

The passwords used in these options must match the passwords used when generating the keystore and truststore. For instructions on generating these files, see Creating a Keystore to Use with JSSE.

The advanced settings:

protocol: (Default: TLS)
algorithm: (Default: SunX509)
store_type: (Default: JKS)
cipher_suites: (Default: TLS_RSA_WITH_AES_128_CBC_SHA,TLS_RSA_WITH_AES_256_CBC_SHA)
require_client_auth: (Default: false)
Enables or disables certificate authentication.
require_endpoint_verification: (Default: false)
Enables or disables host name verification.

Related information: Node-to-node encryption

client_encryption_options

Enables or disables client-to-node encryption. You must also generate keys and provide the appropriate key and truststore locations and passwords. There are no custom encryption options are currently enabled for Cassandra. Available options:

enabled: (Default: false)
To enable, set to true.
keystore: (Default: conf/.keystore)
The location of a Java keystore (JKS) suitable for use with Java Secure Socket Extension (JSSE), which is the Java version of the Secure Sockets Layer (SSL), and Transport Layer Security (TLS) protocols. The keystore contains the private key used to encrypt outgoing messages.
keystore_password: (Default: cassandra)
Password for the keystore. This must match the password used when generating the keystore and truststore.
require_client_auth: (Default: false)
Enables or disables certificate authentication. (Available starting with Cassandra 1.2.3.)
truststore: (Default: conf/.truststore)
Set this property if require_client_auth is true.
truststore_password: truststore_password
Set if require_client_auth is true.

Advanced settings:

protocol: (Default: TLS)
algorithm: (Default: SunX509)
store_type: (Default: JKS)
cipher_suites: (Default: TLS_RSA_WITH_AES_128_CBC_SHA,TLS_RSA_WITH_AES_256_CBC_SHA)

Related information: Client-to-node encryption

transparent_data_encryption_options

Enables encryption of data at rest (on-disk). Recommendation: download and install the Java Cryptography Extension (JCE) Unlimited Strength Jurisdiction Policy Files for your version of the JDK.

Cassandra supports transparent data encryption for the following file types:

Available options:

enabled: (Default: false)
chunk_length_kb: (Default: 64)
cipher: options:
- AES
- CBC
- PKCS5Padding
key_alias: testing:1
iv_length: 16
Note: iv_length is commented out in the default cassandra.yaml file. Uncomment only if cipher is set to AES. The value must be 16 (bytes).
key_provider:
- class_name: org.apache.cassandra.security.JKSKeyProvider
  parameters:
  - keystore: conf/.keystore
  - keystore_password: cassandra
  - store_type: JCEKS
  - key_password: cassandra

ssl_storage_port: (Default: 7001) The SSL port for encrypted communication. Unused unless enabled in encryption_options.

native_transport_port_ssl: (Default: 9142) In Cassandra 3.0 and later, an additional dedicated port can be designated for encryption. If client encryption is enabled and native_transport_port_ssl is disabled, the native_transport_port (default: 9042) will encrypt all traffic. To use both unencrypted and encrypted traffic, enable native_transport_port_ssl

The location of the cassandra-env.sh file depends on the type of installation:

Package installations	/etc/cassandra/cassandra-env.sh
Tarball installations	`install_location`/conf/cassandra-env.sh

Package installations	/etc/cassandra/cassandra-rackdc.properties
Tarball installations	`install_location`/conf/cassandra-rackdc.properties

Package installations	/etc/cassandra/cassandra-topology.properties
Tarball installations	`install_location`/conf/cassandra-topology.properties