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https://issues.apache.org/jira/browse/HADOOP-17749?focusedWorklogId=613844&page=com.atlassian.jira.plugin.system.issuetabpanels:worklog-tabpanel#worklog-613844
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ASF GitHub Bot logged work on HADOOP-17749:
-------------------------------------------
Author: ASF GitHub Bot
Created on: 23/Jun/21 07:26
Start Date: 23/Jun/21 07:26
Worklog Time Spent: 10m
Work Description: liangxs commented on a change in pull request #3080:
URL: https://github.com/apache/hadoop/pull/3080#discussion_r656829433
##########
File path:
hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/net/SocketIOWithTimeout.java
##########
@@ -426,34 +407,44 @@ private synchronized SelectorInfo get(SelectableChannel
channel)
*
* @param info
*/
- private synchronized void release(SelectorInfo info) {
+ private static void release(SelectorInfo info) {
long now = Time.now();
trimIdleSelectors(now);
info.lastActivityTime = now;
- info.queue.addLast(info);
+ // SelectorInfos in queue are sorted by lastActivityTime
+ providerMap.get(info.provider).addLast(info);
}
+ private static AtomicBoolean trimming = new AtomicBoolean(false);
+ private static volatile long lastTrimTime = Time.now();
+
/**
* Closes selectors that are idle for IDLE_TIMEOUT (10 sec). It does not
* traverse the whole list, just over the one that have crossed
* the timeout.
*/
- private void trimIdleSelectors(long now) {
+ private static void trimIdleSelectors(long now) {
+ if (!trimming.compareAndSet(false, true)) {
+ return;
+ }
+ if (now - lastTrimTime < IDLE_TIMEOUT / 2) {
Review comment:
@ferhui I remove this check in new commit.
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Issue Time Tracking
-------------------
Worklog Id: (was: 613844)
Time Spent: 2h 40m (was: 2.5h)
> Remove lock contention in SelectorPool of SocketIOWithTimeout
> -------------------------------------------------------------
>
> Key: HADOOP-17749
> URL: https://issues.apache.org/jira/browse/HADOOP-17749
> Project: Hadoop Common
> Issue Type: Improvement
> Components: common
> Reporter: Xuesen Liang
> Priority: Major
> Labels: pull-request-available
> Time Spent: 2h 40m
> Remaining Estimate: 0h
>
> *SelectorPool* in
> hadoop-common/src/main/java/org/apache/hadoop/net/*SocketIOWithTimeout.java*
> is a point of lock contention.
> For example:
> {code:java}
> $ grep 'waiting to lock <0x00007f7d94006d90>' 63692.jstack | uniq -c
> 1005 - waiting to lock <0x00007f7d94006d90> (a
> org.apache.hadoop.net.SocketIOWithTimeout$SelectorPool)
> {code}
> and the thread stack is as follows:
> {code:java}
> "IPC Client (324579982) connection to /100.10.6.10:60020 from user_00" #14139
> daemon prio=5 os_prio=0 tid=0x00007f7374039000 nid=0x85cc waiting for monitor
> entry [0x00007f6f45939000]
> java.lang.Thread.State: BLOCKED (on object monitor)
> at
> org.apache.hadoop.net.SocketIOWithTimeout$SelectorPool.get(SocketIOWithTimeout.java:390)
> - waiting to lock <0x00007f7d94006d90> (a
> org.apache.hadoop.net.SocketIOWithTimeout$SelectorPool)
> at
> org.apache.hadoop.net.SocketIOWithTimeout$SelectorPool.select(SocketIOWithTimeout.java:325)
> at
> org.apache.hadoop.net.SocketIOWithTimeout.doIO(SocketIOWithTimeout.java:157)
> at org.apache.hadoop.net.SocketInputStream.read(SocketInputStream.java:161)
> at org.apache.hadoop.net.SocketInputStream.read(SocketInputStream.java:131)
> at java.io.FilterInputStream.read(FilterInputStream.java:133)
> at java.io.BufferedInputStream.fill(BufferedInputStream.java:246)
> at java.io.BufferedInputStream.read(BufferedInputStream.java:265)
> - locked <0x00007fa818caf258> (a java.io.BufferedInputStream)
> at java.io.DataInputStream.readInt(DataInputStream.java:387)
> at
> org.apache.hadoop.hbase.ipc.RpcClientImpl$Connection.readResponse(RpcClientImpl.java:967)
> at
> org.apache.hadoop.hbase.ipc.RpcClientImpl$Connection.run(RpcClientImpl.java:568)
> {code}
> We should remove the lock contention.
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