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• Cassandra fails with the "java.lang.OutOfMemoryError: Direct buffer memory" error

  With some large databases, Cassandra may fail with the following error:

  Code Block

  java.lang.OutOfMemoryError: Direct buffer memory at java.nio.Bits.reserveMemory(Bits.java:694) at java.nio.DirectByteBuffer.<init>(DirectByteBuffer.java:123) at java.nio.ByteBuffer.allocateDirect(ByteBuffer.java:311) at org.apache.cassandra.utils.memory.BufferPool.allocate(BufferPool.java:110) at org.apache.cassandra.utils.memory.BufferPool.access$1000(BufferPool.java:46) at org.apache.cassandra.utils.memory.BufferPool$LocalPool.allocate(BufferPool.java:407) at org.apache.cassandra.utils.memory.BufferPool$LocalPool.access$000(BufferPool.java:334) at org.apache.cassandra.utils.memory.BufferPool.takeFromPool(BufferPool.java:122) at org.apache.cassandra.utils.memory.BufferPool.get(BufferPool.java:94) at org.apache.cassandra.cache.ChunkCache.load(ChunkCache.java:155) at org.apache.cassandra.cache.ChunkCache.load(ChunkCache.java:39)

  
  

  To solve the problem do one of the following:

  • Increase the memory (Xmx VM option) for Cassandra until the migration is successful.
  • Set file_cache_size_in_mb: 0 In the cassandra.yaml file to disable the chunk cache completely.

  
  

  "All commit element IDs" index is corrupted

  If the "all commit element IDs" index is corrupted, migration may fail and print an error of the following format into the Migrator's log file:

  Code Block
  It has been detected that "all commit element IDs" index is corrupted at revision <revision> of resource <resource.id>

  
  

  To solve the problem

  ---

  1. Wait until all selected projects finish migrating.
  2. Stop the Migrator (backend) process.

  3. At the end of the migrator's application.conf file, add the following line:

     Code Block
     esi.migration.source-revision-all-object-ids-getter.prefer-bfs=true

  4. Start the Migrator and retry the migration of the failed project from the Migrator GUI.

  
  With this setting in place, it is expected that the migration progress will be much slower so it is recommended to finish the affected project with this setting and then revert back.

  
  The "java.net.SocketException: Too many open files" error appears during migration

  This error usually means that the Cassandra or Teamwork Cloud process is running into system-imposed limits on a number of open files.

  
  

  To solve the problem

  ---

  1. Set the following limits in /etc/security/limits.conf.

     Code Block
     localUser hard nofile 50000 localUser hard nproc 50000 localUser soft nofile 40000 localUser soft nproc 40000 cassandra hard nofile 50000 cassandra hard nproc 50000 cassandra soft nofile 40000 cassandra soft nproc 40000 root hard nofile 50000 root hard nproc 50000 root soft nofile 40000 root soft nproc 40000

  2. Restart the processes.

  
  Limits are configurable to separate users (like the Cassandra user that runs Cassandra or the Teamwork Cloud user that runs the Teamwork Cloud service). For more information, see https://linux.die.net/man/5/limits.conf.
  
  

  The "com.datastax.driver.core.exceptions.AuthenticationException" exception is shown in the log file

  The following exception is shown in the log file:

  Code Block
  Error while trying to activate [com.nomagic.esi.server.core.a.d.c, main] com.datastax.driver.core.exceptions.AuthenticationException: Authentication error on host FQDN/IP: Provided username cassandra and/or password are incorrect

  To solve the problem:

  • Add the following configuration block to application.conf of the migrator artifact:

    Code Block
    title application.conf
    authentication-enabled = true authentication { username = your_cassandra_username password = your_cassandra_password }