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https://issues.apache.org/jira/browse/HBASE-16275?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15390527#comment-15390527
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Yu Li commented on HBASE-16275:
-------------------------------
Checking TestProcedureManager in local, we will see below exception:
{noformat}
2016-07-23 12:17:05,583 FATAL [M:0;localhost:57006] master.HMaster(2154):
Unhandled: inconsistent range
java.lang.IllegalArgumentException: inconsistent range
at
java.util.concurrent.ConcurrentSkipListMap$SubMap.<init>(ConcurrentSkipListMap.java:2506)
at
java.util.concurrent.ConcurrentSkipListMap.subMap(ConcurrentSkipListMap.java:1984)
at
org.apache.hadoop.hbase.master.ServerManager.findServerWithSameHostnamePortWithLock(ServerManager.java:448)
at
org.apache.hadoop.hbase.master.ServerManager.checkAndRecordNewServer(ServerManager.java:357)
at
org.apache.hadoop.hbase.master.ServerManager.regionServerStartup(ServerManager.java:267)
at
org.apache.hadoop.hbase.master.MasterRpcServices.regionServerStartup(MasterRpcServices.java:269)
at
org.apache.hadoop.hbase.regionserver.HRegionServer.reportForDuty(HRegionServer.java:2362)
at
org.apache.hadoop.hbase.regionserver.HRegionServer.run(HRegionServer.java:946)
{noformat}
Checking the code, the problem is that {{ServerName#compareTo}} will do a force
cast when comparing startcode:
{code}
return (int)(this.getStartcode() - other.getStartcode());
{code}
When we cast the result of {{0 - Long.MAX_VALUE}} to int, it will return 1,
making fromKey larger than toKey when calling {{CSLM#subMap}}. Simply test
{code}
long x = 0L - Long.MAX_VALUE;
System.out.println(x);
System.out.println((int) x);
{code}
and we could see below result:
{noformat}
-9223372036854775807
1
{noformat}
Please resolve the above problem (well, to be fair, this actually is a bug of
{{ServerName#compareTo}}, but still...) and update the patch [~huaxiang],
thanks.
> Change ServerManager#onlineServers from ConcurrentHashMap to
> ConcurrentSkipListMap
> ----------------------------------------------------------------------------------
>
> Key: HBASE-16275
> URL: https://issues.apache.org/jira/browse/HBASE-16275
> Project: HBase
> Issue Type: Improvement
> Reporter: huaxiang sun
> Assignee: huaxiang sun
> Priority: Minor
> Attachments: HBASE-16275-v001.patch
>
>
> In Class ServerManager, onlineServers is declared as ConcurrentHashMap. In
> findServerWithSameHostnamePortWithLock(), it has to do a loop to find if
> there is a ServerName with same host:port pair. If replaced with
> ConcurrentSkipListMap, findServerWithSameHostnamePortWithLock() can be
> replaced with a O(logN) implementation.
> I run some performance comparison(test the function only), it seems that
> there is no difference if there are 1000 servers. With more servers,
> ConcurrentSkipListMap implementation is going to win big.
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