org.apache.activemq.artemis.cli.commands.util

Class SyncCalculation

java.lang.Object

org.apache.activemq.artemis.cli.commands.util.SyncCalculation

public class SyncCalculation
extends Object

It will perform a simple test to evaluate how many syncs a disk can make per second * *

Constructor Summary

Constructors

Constructor and Description
SyncCalculation()

Method Summary

Modifier and Type	Method and Description
static long	syncTest(File datafolder, int blockSize, int blocks, int tries, boolean verbose, boolean fsync, boolean syncWrites, String fileName, int maxAIO, JournalType journalType) It will perform tries write tests of blockSize * blocks bytes and returning the lowest elapsed time to perform a try.
static long	toNanos(long time, long blocks, boolean verbose)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

SyncCalculation

public SyncCalculation()

Method Detail

syncTest

public static long syncTest(File datafolder,
                            int blockSize,
                            int blocks,
                            int tries,
                            boolean verbose,
                            boolean fsync,
                            boolean syncWrites,
                            String fileName,
                            int maxAIO,
                            JournalType journalType)
                     throws Exception

It will perform tries write tests of blockSize * blocks bytes and returning the lowest elapsed time to perform a try.

Please configure blocks >= -XX:CompileThreshold (ie by default on most JVMs is 10000) to favour the best JIT/OSR compilation (ie: Just In Time/On Stack Replacement) if the test is running on a temporary file-system (eg: tmpfs on Linux) or without fsync.

NOTE: The write latencies are provided only if verbose && !(journalType == JournalType.ASYNCIO && !syncWrites) (ie are used effective synchronous writes).

Parameters:

datafolder - the folder where the journal files will be stored

blockSize - the size in bytes of each write on the journal

blocks - the number of blockSize writes performed on each try

tries - the number of tests

verbose - true to make the output verbose, false otherwise

fsync - if true the test is performing full durable writes, false otherwise

syncWrites - if true each write is performed only if the previous one is completed, false otherwise (ie each try will wait only the last write)

fileName - the name of the journal file used for the test

maxAIO - the max number of in-flight IO requests (if journalType will support it)

journalType - the JournalType used for the tests

Returns:

the lowest elapsed time (in TimeUnit.MILLISECONDS) to perform a try

Throws:

Exception

toNanos

public static long toNanos(long time,
                           long blocks,
                           boolean verbose)