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https://issues.apache.org/jira/browse/ARTEMIS-1476?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16216275#comment-16216275
]
ASF GitHub Bot commented on ARTEMIS-1476:
-----------------------------------------
Github user franz1981 commented on a diff in the pull request:
https://github.com/apache/activemq-artemis/pull/1605#discussion_r146450033
--- Diff:
artemis-cli/src/main/java/org/apache/activemq/artemis/cli/commands/util/SyncCalculation.java
---
@@ -69,74 +171,55 @@ public static long syncTest(File datafolder,
file.close();
- long[] result = new long[tries];
+ final long[] elapsedMillis = new long[tries];
- byte[] block = new byte[blockSize];
-
- for (int i = 0; i < block.length; i++) {
- block[i] = (byte) 't';
- }
-
- ByteBuffer bufferBlock = factory.newBuffer(blockSize);
- bufferBlock.put(block);
- bufferBlock.position(0);
-
- final ReusableLatch latch = new ReusableLatch(0);
-
- IOCallback callback = new IOCallback() {
- @Override
- public void done() {
- latch.countDown();
- }
-
- @Override
- public void onError(int errorCode, String errorMessage) {
-
- }
- };
-
- DecimalFormat dcformat = new DecimalFormat("###.##");
+ final DecimalFormat dcformat = new DecimalFormat("###.##");
for (int ntry = 0; ntry < tries; ntry++) {
+ //perform a gc on each test iteration to help cleanup of
callbacks/garbage
+ System.gc();
--- End diff --
Good point, I'm addressing all these things, but I need feedback on that
too :)
I see 2 options here:
1) preallocate and cache the `blocks` IO callbacks (but could be a large
number too) in order to be garbage free again
2) let the IO callbacks to size the (young) GC regions in the first test
but uses a better way (ie more reliable) to be sure GC won't affect the
measurements
I'm pushing the second solution right now, using the code used by the
official microbenchmark tool of the OpenJDK JMH
(http://hg.openjdk.java.net/code-tools/jmh/file/e96cad1fc480/jmh-core/src/main/java/org/openjdk/jmh/runner/BaseRunner.java#l309)
to perform reliable GC, but feel free to give me feedbacks and suggest me to
try the first one too, although I'm not 100% sure could be a better way (cachin
a large number of instances in not optimal!!).
> HdrHistogram support on verbose SyncCalculation
> -----------------------------------------------
>
> Key: ARTEMIS-1476
> URL: https://issues.apache.org/jira/browse/ARTEMIS-1476
> Project: ActiveMQ Artemis
> Issue Type: Improvement
> Components: Broker
> Reporter: Francesco Nigro
> Assignee: Francesco Nigro
>
> The SyncCalculation::syncTest could benefit of
> [HdrHistogram|http://hdrhistogram.org/] support to represent the write
> latencies percentile distribution while using it as a CLI command (ie through
> the perf-journal command).
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