cassandra.yaml configuration file

Determines how the database handles commit log disk failures.

Reading from spinning disks is slow so they are buffered with an extra page of 4KB just in case. This is unnecessary for SSDs so buffer only what is required.

Determines how the database handles disk failures.

Configure this property to set the snitch. The most common snitches are:

The gossip seed provider and corresponding addresses of nodes that are designated as contact points in the cluster. A joining node contacts the nodes in the seeds list and establishes a connection to the first available node to discover the members of the cluster and topology.

The token allocation algorithm for vnodes distributes token ranges across nodes in a datacenter based on the number of nodes and the value of num_tokens. With allocate_tokens_for_keyspace, token distribution also considers a specified replication factor, resulting in a more balanced distribution compared to legacy random allocation (without vnodes).

The token allocation algorithm for vnodes distributes token ranges across nodes in a datacenter based on the number of nodes and the value of num_tokens. With allocate_tokens_for_local_replication_factor, token distribution also considers a specified replication factor, resulting in a more balanced distribution compared to legacy random allocation (without vnodes).

When joining a cluster for the first time, this property determines whether the node will request replicas to stream data (default behaviour). If the node is defined as a seed node, it immediately joins the cluster without data.

Set to the node’s public IP address in environments where nodes are only able to communicate across networks using their public IP adresses such as multi-region Amazon EC2 deployments. Otherwise, the node will broadcast on the same address as listen_address.

Manually assign tokens for token range allocation to nodes:

Set to true on nodes with multiple interfaces to enable communication on both listen_address and broadcast_address.

When using vnodes, defines the number of token ranges to assign to the node:

The partitioner determines how data is distributed across the nodes in the cluster.

The rate (in megabytes/second) at which SSTable candidates will be compacted. The faster the database inserts data, the faster the system must compact in order to keep the number of SSTables down.

Determines how HCD allocates memory to the memtable.

The maximum amount of memory to allocate for memtables on JVM heap. When the threshold is reached, writes are blocked until a flush completes.

The maximum amount of memory to allocate for memtables from native memory. When the threshold is reached, writes are blocked until a flush completes.

The threshold that triggers a flush based on the ratio of memtable size to the maximum memory size permitted for memtables.

The total number of memtables that can be flushed concurrently as well as the number of flush writer threads per disk. Factors into the memtable flush threshold calculation.

When enabled (set to true), a snapshot is taken before DROP KEYPACE, DROP TABLE, or TRUNCATE TABLE is executed.

When enabled (set to true), create hard links to each SSTable that has been flushed or streamed in the backups/ subdirectory of the keyspace data.

When enabled (set to true), a snapshot is taken before each compaction task. The snapshot may be used as a rollback position in an upgrade. Usage is limited since the general recommendation is to take backups before performing an upgrade.

Time interval between commit log syncs to disk. Only set with periodic sync mode, otherwise an exception will be logged.

The minimum interval between disk syncs. Only set with group sync mode, otherwise an exception will be logged.

Deprecated. The maximum delay between disk syncs. No longer used.

The size of individual commit log file segments. A small size means more frequent flushes leading to small SSTables which put pressure on compaction.

The maximum allowed size of a mutation (the payload size of a write request) which defaults to half of the commit log segment (commitlog_segment_size_in_mb). If explicitly set, you must set commitlog_segment_size_in_mb to at least twice the value of max_mutation_size_in_kb.

The maximum disk space for commit logs on disk.

By default, the commit log is not compressed. To enable compression, specify the compression library to use.

The compressor for hint files. When not set, the database does not compress hints files.

hints_compression:
  - class_name: LZ4Compressor
    parameters:
     - lz4_compressor_type: fast

Enables CDC functionality on a per-node basis when set to true.

Maximum disk space to use for CDC logs. If the limit is reached, HCD throws WriteTimeoutException on mutations, including CDC-enabled tables. A CDCCompactor (a consumer) is responsible for parsing the raw CDC logs and deleting them when parsing is completed.

Interval between disk space checks when cdc_total_space_in_mb limit is reached.

The number of compaction threads allowed to run simultaneously. 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.

The number of repair validation threads allowed to run simultaneously.

The number of view builder tasks allowed to run simultaneously if materialized views are enabled (experimental).

The size of the SSTable candidates to trigger preemptive opening of compaction output.

Granularity of the index of rows within a partition. For huge rows, decrease this setting to improve seek time.

Maximum memory to use for caching SSTable chunks and buffer pools. Allocated from native memory in addition to heap.

Only applies to BIG format SSTables, which have a partition key cache.

The classname of the row cache provider to use if row_cache_size_in_mb and row_cache_save_period aren’t 0:

Maximum size of the row cache in memory. The row cache can improve read latency, but it requires a significant amount of memory because it contains the entire row. Use the row cache only for frequently read rows or static rows. If the cache is too small, it might be too cold at startup and perform suboptimally until it has warmed up and recached the most frequently read rows.

The time in seconds after which row cache keys are saved to saved_caches_directory. Only applies if row_cache_size_in_mb is greater than 0.

The number of keys from the row cache to save if row_cache_save_period is greater than 0.

The size of the counter cache. It doesn’t require as much memory as other caches because only the local (clock, count) tuple of a counter cell is kept in memory, not the whole counter.

The time in seconds after which the database saves counter cache keys to saved_caches_directory. This keeps the cache warm through restarts.

The number of keys from the counter cache to save if counter_cache_save_period is greater than 0.

Maximum network bandwidth for file transfers (streaming) between datacenters. Set to a value less or equal to stream_throughput_outbound_megabits_per_sec.

Enables the Zero Copy Streaming feature where eligible SSTables are streamed in their entirety between nodes instead of individual partitions, transferring data at a significantly faster rate.

Maximum network bandwidth permitted for all outbound file transfers (streaming) on a node.

Interval to send keep-alive messages to prevent reset connections during streaming. The streaming session fails when a keep-alive message is not received for two keep-alive cycles equivalent to 10 minutes by default (2 x 300 seconds).