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https://issues.apache.org/jira/browse/IGNITE-29099?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Nikita Amelchev updated IGNITE-29099:
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Attachment: JmhCacheTxFullSyncBenchmark.java
> Avoid boxing of cache ID and message direct type on the transactional hot path
> ------------------------------------------------------------------------------
>
> Key: IGNITE-29099
> URL: https://issues.apache.org/jira/browse/IGNITE-29099
> Project: Ignite
> Issue Type: Improvement
> Reporter: Nikita Amelchev
> Assignee: Nikita Amelchev
> Priority: Minor
> Attachments: JmhCacheTxFullSyncBenchmark.java
>
>
> JFR profiling of a FULL_SYNC transactional put (3 server nodes, 2 backups)
> shows three allocation sites that box a primitive map key on every call:
> * {{GridCacheSharedContext#cacheContext(int)}} and
> {{#cacheObjectContext(int)}} - lookup in {{ConcurrentHashMap<Integer,
> GridCacheContext>}}. A cache ID is a hash of the cache name, so it misses the
> {{Integer}} cache. Called several times per transaction on each node:
> {{IgniteTxEntryMarshaller}}, {{IgniteTxEntry#initializeContext}},
> {{IgniteTxStateImpl#validateTopology}}, {{IgniteTxStateImpl#onTxEnd}}.
> * {{TcpCommunicationMetricsListener#updateMessageTypeMap}} - {{Map<Short,
> String>#containsKey(short)}} for every sent and received message.
> Together these sites produce 2-3% of all allocations of a transaction.
> h3. Proposed change
> * {{GridCacheSharedContext}}: add a volatile copy-on-write
> {{IntMap<GridCacheContext>}} snapshot of {{ctxMap}}, rebuilt in
> {{addCacheContext}} and {{removeCacheContext}}; both lookups read the
> snapshot.
> * {{TcpCommunicationMetricsListener}}: replace {{Map<Short, String>}} with a
> copy-on-write {{IntMap<String>}}.
> h3. Result
> JMH, {{gc.alloc.rate.norm}}, implicit put: the three sites disappear from the
> JFR profile, allocations per transaction drop by about 1.7% (28.6 KB -> 28.1
> KB), throughput is unchanged.
> {{JmhCacheTxFullSyncBenchmark}} is added to reproduce the measurements.
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