ZOOKEEPER-3961: Improve error message for zookeeper.intBufferStarting…

[rpinzon]

…SizeBytes config

[rpinzon]

I was considering moving the variable declaration at line 242 to line 240. In this way, the documentation provided from line 236 to 239 will be visible from external caller code (src/main/java/org/apache/zookeeper/server/ServerCnxn.java:198).

    /**
     * Starting size of read and write ByteArroyOuputBuffers. Default is 32 bytes.
     * Flag not used for small transfers like connectResponses.
     */
    public static final int intBufferStartingSizeBytes;
    public static final String INT_BUFFER_STARTING_SIZE_BYTES = "zookeeper.intBufferStartingSizeBytes";
    public static final int DEFAULT_STARTING_BUFFER_SIZE = 1024;

instead of

    /**
     * Starting size of read and write ByteArroyOuputBuffers. Default is 32 bytes.
     * Flag not used for small transfers like connectResponses.
     */
    public static final String INT_BUFFER_STARTING_SIZE_BYTES = "zookeeper.intBufferStartingSizeBytes";
    public static final int DEFAULT_STARTING_BUFFER_SIZE = 1024;
    public static final int intBufferStartingSizeBytes;

Does it make sense?

[maoling]

• Test it.
  2021-07-11 18:50:41,011 [myid:] - ERROR [main:ZooKeeperServer@258] - Buffer starting size (31) must be greater than or equal to 32. Configure with "-Dzookeeper.intBufferStartingSizeBytes=<size>"
• @rpinzon Thanks for your contribution.