[IGNITE-23313] Avoid useing fulfilled hybrid time in SchemaVersions#schemaVersionAtNow

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 3.0
• Fix Version/s: 3.0
• Labels: ignite-3
• Ignite Flags: Docs Required, Release Notes Required
• Assignee: Vladislav Pyatkov
• Reporter: Vladislav Pyatkov
• Created: 30/Sep/24 07:17
• Updated: 26/Nov/24 13:35
• Resolved: 26/Nov/24 13:35

Description

Motivation

Contantion is the main issue with one-node performance. The hybrid clock is a natural contraction in our algorithm. Hence, reducing the number of HybridClock#now invocations increases performance.

hybridClock:nowLong-:java.lang.Exception: 
	at org.apache.ignite.internal.util.IgniteUtils.dumpStack(IgniteUtils.java:682)
	at org.apache.ignite.internal.hlc.HybridClockImpl.nowLong(HybridClockImpl.java:76)
	at org.apache.ignite.internal.hlc.HybridClockImpl.now(HybridClockImpl.java:108)
	at org.apache.ignite.internal.hlc.ClockServiceImpl.now(ClockServiceImpl.java:43)
	at org.apache.ignite.internal.table.distributed.schema.SchemaVersionsImpl.schemaVersionAtNow(SchemaVersionsImpl.java:86)
	at org.apache.ignite.internal.table.AbstractTableView.withSchemaSync(AbstractTableView.java:139)
	at org.apache.ignite.internal.table.AbstractTableView.withSchemaSync(AbstractTableView.java:134)
	at org.apache.ignite.internal.table.AbstractTableView.doOperation(AbstractTableView.java:112)
	at org.apache.ignite.internal.table.KeyValueBinaryViewImpl.getAsync(KeyValueBinaryViewImpl.java:117)
	at org.apache.ignite.internal.table.KeyValueBinaryViewImpl.get(KeyValueBinaryViewImpl.java:104)
	at org.apache.ignite.internal.table.KeyValueBinaryViewImpl.get(KeyValueBinaryViewImpl.java:74)
	at org.apache.ignite.internal.table.PublicApiThreadingKeyValueView.lambda$get$0(PublicApiThreadingKeyValueView.java:57)
	at org.apache.ignite.internal.thread.PublicApiThreading.executeWithRole(PublicApiThreading.java:144)
	at org.apache.ignite.internal.thread.PublicApiThreading.execUserSyncOperation(PublicApiThreading.java:102)
	at org.apache.ignite.internal.table.PublicApiThreadingViewBase.executeSyncOp(PublicApiThreadingViewBase.java:107)
	at org.apache.ignite.internal.table.PublicApiThreadingKeyValueView.get(PublicApiThreadingKeyValueView.java:57)
	at org.apache.ignite.internal.restart.RestartProofKeyValueView.lambda$get$0(RestartProofKeyValueView.java:58)
	at org.apache.ignite.internal.restart.RestartProofApiObject.lambda$attached$0(RestartProofApiObject.java:46)
	at org.apache.ignite.internal.restart.IgniteAttachmentLock.attached(IgniteAttachmentLock.java:59)
	at org.apache.ignite.internal.restart.RestartProofApiObject.attached(RestartProofApiObject.java:46)
	at org.apache.ignite.internal.restart.RestartProofKeyValueView.get(RestartProofKeyValueView.java:58)
	at org.apache.ignite.internal.benchmark.SelectBenchmark.kvGet(SelectBenchmark.java:175)
	at org.apache.ignite.internal.benchmark.jmh_generated.SelectBenchmark_kvGet_jmhTest.kvGet_avgt_jmhStub(SelectBenchmark_kvGet_jmhTest.java:238)
	at org.apache.ignite.internal.benchmark.jmh_generated.SelectBenchmark_kvGet_jmhTest.kvGet_AverageTime(SelectBenchmark_kvGet_jmhTest.java:177)
	at jdk.internal.reflect.GeneratedMethodAccessor20.invoke(Unknown Source)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.base/java.lang.reflect.Method.invoke(Method.java:566)
	at org.openjdk.jmh.runner.BenchmarkHandler$BenchmarkTask.call(BenchmarkHandler.java:527)
	at org.openjdk.jmh.runner.BenchmarkHandler$BenchmarkTask.call(BenchmarkHandler.java:504)
	at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
	at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:515)
	at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
	at java.base/java.lang.Thread.run(Thread.java:829)

Here the call stack to determine scema version in case of an implicit transaction. But if the transaction is alredy created for at this time, we can use a transaction start time.

Implementation notes

1. In the case above we ought to create an implicit transaction instance before the palce. (it could be difficult, but it will be need in the future)
2. We can use a fast, not continuous method of getting timestamps based on current astronomical time. It coud be the method HybridClockSyncImpl#currentTime.

Definition of done

Do not use hybrid time in the schemaVersionAtNow method because there is no reason to capture this timestamp.

Issue Links

• is related to: IGNITE-23199 Investigate GET scalability issues
• links to: GitHub Pull Request #4760
• links to: GitHub Pull Request #4790