Package org.elasticsearch.index.seqno

Class SequenceNumbers

java.lang.Object
org.elasticsearch.index.seqno.SequenceNumbers
public class SequenceNumbers extends Object
A utility class for handling sequence numbers.

  • Field Details

    • LOCAL_CHECKPOINT_KEY

      public static final String LOCAL_CHECKPOINT_KEY
      See Also:
      Constant Field Values

    • MAX_SEQ_NO

      public static final String MAX_SEQ_NO
      See Also:
      Constant Field Values

    • UNASSIGNED_SEQ_NO

      public static final long UNASSIGNED_SEQ_NO
      Represents an unassigned sequence number (e.g., can be used on primary operations before they are executed).
      See Also:
      Constant Field Values

    • NO_OPS_PERFORMED

      public static final long NO_OPS_PERFORMED
      Represents no operations have been performed on the shard. Initial value of a sequence number.
      See Also:
      Constant Field Values

    • UNASSIGNED_PRIMARY_TERM

      public static final long UNASSIGNED_PRIMARY_TERM
      Represents an unassigned primary term (e.g., when a primary shard was not yet allocated)
      See Also:
      Constant Field Values

  • Constructor Details

    • SequenceNumbers

      public SequenceNumbers()

  • Method Details

    • loadSeqNoInfoFromLuceneCommit

      public static SequenceNumbers.CommitInfo loadSeqNoInfoFromLuceneCommit(Iterable<Map.Entry<String,String>> commitData)
      Reads the sequence number stats from the commit data (maximum sequence number and local checkpoint).
      Parameters:
      commitData - the commit data
      Returns:
      the sequence number stats

    • min

      public static long min(long minSeqNo, long seqNo)
      Compute the minimum of the given current minimum sequence number and the specified sequence number, accounting for the fact that the current minimum sequence number could be NO_OPS_PERFORMED or UNASSIGNED_SEQ_NO. When the current minimum sequence number is not NO_OPS_PERFORMED nor UNASSIGNED_SEQ_NO, the specified sequence number must not be UNASSIGNED_SEQ_NO.
      Parameters:
      minSeqNo - the current minimum sequence number
      seqNo - the specified sequence number
      Returns:
      the new minimum sequence number

    • max

      public static long max(long maxSeqNo, long seqNo)
      Compute the maximum of the given current maximum sequence number and the specified sequence number, accounting for the fact that the current maximum sequence number could be NO_OPS_PERFORMED or UNASSIGNED_SEQ_NO. When the current maximum sequence number is not NO_OPS_PERFORMED nor UNASSIGNED_SEQ_NO, the specified sequence number must not be UNASSIGNED_SEQ_NO.
      Parameters:
      maxSeqNo - the current maximum sequence number
      seqNo - the specified sequence number
      Returns:
      the new maximum sequence number