Upgrading DataStax Enterprise 5.1 to 6.0

Upgrade restrictions and limitations

Restrictions and limitations apply while a cluster is in a partially upgraded state. The cluster continues to work as though it were on the earlier version of DataStax Enterprise until all of the nodes in the cluster are upgraded.

Advanced preparation for upgrading DSE Search nodes

Before continuing, complete all the advanced preparation steps on DSE Search nodes while DSE 5.1 is still running.

1. Ensure all use of HTTP API writes are changed to use CQL commands for updates and inserts.
2. Edit the search index config and make these changes, as needed. See Search index config for valid options to change query behavior for search indexes.
   • Remove the unsupported dataDir option. You can still set the location of search indexes.
   • Remove mergePolicy, maxMergeDocs, and mergeFactor. For example:

     <mergeFactor>25</mergeFactor>
     <maxMergeDocs>...
     <mergePolicy>...

     Use mergePolicyFactory instead, and add mergeScheduler:

     <mergeScheduler class="org.apache.lucene.index.ConcurrentMergeScheduler">
         <int name="maxThreadCount">16</int>
         <int name="maxMergeCount">32</int>
     </mergeScheduler>
     ...
     <mergePolicyFactory class="org.apache.solr.index.TieredMergePolicyFactory">
       <int name="maxMergeAtOnce">10</int>
       <int name="segmentsPerTier">10</int>
     </mergePolicyFactory>

   • Remove any instance of ExtractingRequestHandler.
   • Remove DSENRTCachingDirectoryFactory. Change:

     <directoryFactory name="DirectoryFactory" class="com.datastax.bdp.search.solr.DSENRTCachingDirectoryFactory"/>

     to:

     <directoryFactory name="DirectoryFactory" class="solr.StandardDirectoryFactory"/>

3. Ensure that the catalina.properties and context.xml files are present in the Tomcat conf dir.
   Warning: DSE will not start after the upgrade if those files are missing.
   The default location of the Tomcat conf directory depends on the type of installation:

   • Package installations: /etc/dse/tomcat/conf
   • Tarball installations: installation_location/resources/tomcat/conf
4. If earlier DSE versions use a custom configuration for the Solr UI web.xml, change:

   <filter-class>com.datastax.bdp.search.solr.auth.DseAuthenticationFilter</filter-class>

   to

   <filter-class>com.datastax.bdp.cassandra.auth.http.DseAuthenticationFilter</filter-class>

Advanced preparation for upgrading DSE Graph nodes

Advanced preparation for upgrading DSE Analytics nodes

Before upgrading DSE Analytics nodes:

1. If you programmatically set the shuffle parameter, you must change the code for applications that use conf.set("spark.shuffle.service.port", port). Instead, use dse spark-submit which automatically sets the correct service port based on the authentication state. See Configuring Spark for more information.
2. If DSEFS is enabled, copy CFS hivemetastore directory to dse:

   DSE_HOME/bin/dse hadoop fs -cp cfs://node_ip_address/user/spark/warehouse/ dsefs://node_ip_address/user/spark/warehouse/

3. Cassandra File System (CFS) is removed. Remove the cfs and cfs_archive keyspaces before upgrading. See the From CFS to DSEFS blog post and the Copying data from CFS to DSEFS documentation for more information.

   DROP KEYSPACE cfs

   DROP KEYSPACE cfs_archive

4. Make sure any use of the SPARK_LOCAL_DIRS and SPARK_EXECUTOR_DIRS environment variables match their use as described in Setting environment variables.
5. For applications to use the compatible Spark Jobserver API in DataStax repository, migrate jobs that extend from SparkHiveJob and SparkSqlJob to SparkSessionJob. See example in the DemoSparkSessionJob in the demos directory.

   The default location of the demos directory depends on the type of installation:

   • Package installations: /usr/share/dse/demos
   • Tarball installations: installation_location/demos

Preparing to upgrade

Follow these steps to prepare each node for the upgrade:

1. Upgrade to the latest patch release on your current version. Fixes included in the latest patch release can simplify the upgrade process.
   Get the current DSE version:

   bin/dse -v
   current_dse_version

2. Familiarize yourself with the changes and features in the new release:
   • DataStax Enterprise 6.0 release notes.
   • General upgrading advice for any version. Be sure to read NEWS.txt all the way back to your current version.
   • DataStax Enterprise changes in CHANGES.txt.
   • DataStax driver changes.
3. Before upgrading, be sure that each node has adequate free disk space.
   Determine current DSE data disk space usage:

   sudo du -sh /var/lib/cassandra/data/
   3.9G	/var/lib/cassandra/data/

   Determine available disk space:

   sudo df -hT /
   Filesystem     Type  Size  Used Avail Use% Mounted on
   /dev/sda1      ext4   59G   16G   41G  28% /

   Important: The required space depends on the compaction strategy. See Disk space
4. Replace ITriggers and custom interfaces.

   All custom implementations, including the following interfaces, must be replaced with supported implementations when upgrading to DSE 6.x:

   • The org.apache.cassandra.triggers.ITrigger interface was modified from augment to augmentNonBlocking for non-blocking internal architecture. Updated trigger implementations must be provided on upgraded nodes. If unsure, drop all existing triggers before upgrading. To check for existing triggers:

     SELECT * FROM system_schema.triggers;

     DROP TRIGGER trigger_name ON keyspace_name.table_name;

   • The org.apache.cassandra.index.Index interface was modified to comply with the core storage engine changes. Updated implementations are required. If unsure, drop all existing custom secondary indexes before upgrading, except DSE Search indexes, which do not need to be replaced. To check for existing indexes:

     SELECT * FROM system_schema.indexes;

     DROP INDEX index_name;

   • The org.apache.cassandra.cql3.QueryHandler, org.apache.cassandra.db.commitlog.CommitLogReadHandler, and other extension points have been changed. See QueryHandlers.
   Tip: For help contact the DataStax Services team.
5. Support for Thrift-compatible tables (COMPACT STORAGE) is dropped. Before upgrading, migrate all non-system tables that have COMPACT STORAGE to CQL table format:

   cqlsh -e 'DESCRIBE FULL SCHEMA;' > schema_file

   cat schema_file | while read -d $';\n' line ; do
     if echo "$line"|grep 'COMPACT STORAGE' 2>&1 > /dev/null ; then
       TBL="`echo $line|sed -e 's|^CREATE TABLE \([^ ]*\) .*$|\1|'`"
       if echo "$TBL"|egrep -v '^system' 2>&1 > /dev/null; then
         echo "ALTER TABLE $TBL DROP COMPACT STORAGE;" >> schema-drop-list
       fi
     fi
   done

   cqlsh -f schema-drop-list

   Note: The script above dumps the complete DSE schema to schema_file, uses grep to find lines containing COMPACT STORAGE, and then writes only those table names to schema-drop-list along with the required ALTER TABLE commands. The schema-drop-list file is then read by cqlsh which runs the ALTER TABLE commands contained therein.
   Warning: DSE will not start if tables using COMPACT STORAGE are present.
6. Ensure that keyspace replication factors are correct for your environment:

   cqlsh --execute "DESCRIBE KEYSPACE keyspace-name;" | grep "replication"
   CREATE KEYSPACE keyspace-name WITH replication = {'class': 'NetworkTopologyStrategy, 'replication_factor': '3'}  AND durable_writes = true;

   • Check the keyspace replication factor for analytics keyspaces.
   • Check the keyspace replication factor for system_auth and dse_security keyspaces.
7. Upgrade the SSTables on each node to ensure that all SSTables are on the current version:

   nodetool upgradesstables

   Warning: Failure to upgrade SSTables when required results in a significant performance impact and increased disk usage.

   Tip: Use the --jobs option to set the number of SSTables that upgrade simultaneously. The default setting is 2, which minimizes impact on the cluster. Set to 0 to use all available compaction threads. DataStax recommends running the upgradesstables command on one node at a time or when using racks, one rack at a time.

   If the SSTables are already on the current version, the command returns immediately and no action is taken.

8. Verify the Java runtime version and upgrade to the recommended version.

   java -version
   openjdk version "1.8.0_222"
   OpenJDK Runtime Environment (build 1.8.0_222-8u222-b10-1ubuntu1~18.04.1-b10)
   OpenJDK 64-Bit Server VM (build 25.222-b10, mixed mode)

   • Recommended: OpenJDK 8 (1.8.0_151 minimum)
     Note: Recommendation changed due to the end of public updates for Oracle JRE/JDK 8. See Oracle Java SE Support Roadmap.
   • Supported: Oracle Java SE 8 (JRE or JDK) (1.8.0_151 minimum)
   Important: Although Oracle JRE/JDK 8 is supported, DataStax does more extensive testing on OpenJDK 8.
9. Run nodetool repair to ensure that data on each replica is consistent with data on other nodes:

   nodetool repair -pr

10. Install the libaio package for optimal performance.
    RHEL platforms:

    sudo yum install libaio

    Debian:

    sudo apt-get install libaio1

11. Back up any customized configuration files since they may be overwritten with default values during installation of the new version.
    Tip: If you backed up your installation using instructions in Backing up and restoring DSE, your original configuration files are included in the archive.

Upgrade steps

General post upgrade steps

After all nodes are upgraded, start the OpsCenter Repair Service if required: 6.5 | 6.7 | 6.8.

Post upgrade steps for DSE Search nodes

For DSE Search nodes:

1. The appender SolrValidationErrorAppender and the logger SolrValidationErrorLogger are no longer used and may safely be removed from logback.xml.
2. In contrast to earlier versions, DataStax recommends accepting the new default value of 1024 for back_pressure_threshold_per_core in dse.yaml. See Configuring and tuning indexing performance.
3. Do a full reindex of all encrypted search indexes on each node in your cluster:

   dsetool reload_core keyspace_name.table_name distributed=false reindex=true deleteAll=true 

   Important: Plan sufficient time after the upgrade is complete to reindex with deleteAll=true on all nodes.

Post upgrade steps for DSE Analytics nodes

For DSE Analytics nodes:

1. Check the replication factor for the dse_analytics keyspace, a new keyspace stores all DSE Analytics internal system data. DataStax recommends setting the replication strategy to NetworkTopologyStrategy (NTS) with a replication factor of at least 3 in each of DSE Analytics datacenters. If a datacenter has more nodes, a larger replication factor should be considered.

   To check the replication strategy and factor:

   cqlsh --execute "DESCRIBE KEYSPACE dse_analytics;" | grep "replication"
   CREATE KEYSPACE keyspace-name WITH replication = {'class': 'replication-strategy, 'datacenter-name': 'replication-factor'};   

2. If you are using Spark SQL tables, migrate them to the new Hive metastore format:

   dse client-tool spark metastore migrate --from 5.1.0 --to 6.0.0

3. Spark Jobserver uses DSE custom version 8.0.4.45. Ensure that applications use the compatible Spark Jobserver API from the DataStax repository.

Warning messages during and after upgrade

You can ignore some log messages that occur during and after an upgrade:

• Some gremlin_server properties in earlier versions of DSE are no longer required. If properties exist in the dse.yaml file after upgrading, logs display warnings similar to:

  WARN  [main] 2017-08-31 12:25:30,523 GREMLIN DseWebSocketChannelizer.java:149 - Configuration for the org.apache.tinkerpop.gremlin.driver.ser.GraphSONMessageSerializerGremlinV1d0 serializer in dse.yaml overrides the DSE default - typically it is best to allow DSE to configure these.

  You can ignore these warnings or modify dse.yaml so that only the required gremlin server properties are present.

Locking DSE package versions

If you have upgraded a DSE package installation, you can prevent future unintended upgrades.

RHEL yum installations

sudo yum versionlock clear

For details on the versionlock command, see http://man7.org/linux/man-pages/man1/yum-versionlock.1.html.

Debian apt-get installations

sudo apt-mark hold dse-*

sudo apt-mark unhold dse-*

For details on the apt-mark command, see http://manpages.ubuntu.com/manpages/bionic/man8/apt-mark.8.html.