[
https://issues.apache.org/jira/browse/HBASE-21926?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16793798#comment-16793798
]
Andrew Purtell commented on HBASE-21926:
----------------------------------------
I'm going to ignore further ImportOrder checkstyle warnings, because it doesn't
seem to matter where the import is placed, there is still a warning. Tired of
guessing what is the right answer. As this is the only checkstyle warning the
patch looks good IMHO.
The javac warning is for a file untouched by this patch, StaticUserWebFilter.
The whitespace warning will be fixed on commit with git am --whitespace=fix.
The patch has been confirmed to work with manual testing.
What else needs to be done here? I think it is ready. I need a +1 please
> Profiler servlet
> ----------------
>
> Key: HBASE-21926
> URL: https://issues.apache.org/jira/browse/HBASE-21926
> Project: HBase
> Issue Type: New Feature
> Components: master, Operability, regionserver
> Reporter: Andrew Purtell
> Assignee: Andrew Purtell
> Priority: Major
> Fix For: 3.0.0, 1.5.0, 2.3.0
>
> Attachments: 1.png, 2.png, 3.png, 4.png, HBASE-21926-branch-1.patch,
> HBASE-21926-branch-1.patch, HBASE-21926-branch-1.patch, HBASE-21926.patch,
> HBASE-21926.patch, HBASE-21926.patch
>
>
> HIVE-20202 describes how Hive added a web endpoint for online in production
> profiling based on async-profiler. The endpoint was added as a servlet to
> httpserver and supports retrieval of flamegraphs compiled from the profiler
> trace. Async profiler
> ([https://github.com/jvm-profiling-tools/async-profiler] ) can also profile
> heap allocations, lock contention, and HW performance counters in addition to
> CPU.
> The profiling overhead is pretty low and is safe to run in production. The
> async-profiler project measured and describes CPU and memory overheads on
> these issues:
> [https://github.com/jvm-profiling-tools/async-profiler/issues/14] and
> [https://github.com/jvm-profiling-tools/async-profiler/issues/131]
> We have an httpserver based servlet stack so we can use HIVE-20202 as an
> implementation template for a similar feature for HBase daemons. Ideally we
> achieve these requirements:
> * Retrieve flamegraph SVG generated from latest profile trace.
> * Online enable and disable of profiling activity. (async-profiler does not
> do instrumentation based profiling so this should not cause the code gen
> related perf problems of that other approach and can be safely toggled on and
> off while under production load.)
> * CPU profiling.
> * ALLOCATION profiling.
>
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
