[jira] [Commented] (HBASE-9393) Hbase does not closing a closed socket resulting in many CLOSE_WAIT

[Sean Busbey (JIRA)]

    [ 
https://issues.apache.org/jira/browse/HBASE-9393?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15181382#comment-15181382
 ] 

Sean Busbey commented on HBASE-9393:
------------------------------------

Can we do the initialization in the constructor (and make the related instance 
variables final) rather than rely on doing this lazy initialization?

{code}
+            } catch (Exception e) {
+              LOG.warn("Failed to find 'unbuffer' method in class " + 
streamClass
+                  + " . So there may be a TCP socket connection "
+                  + "left open in CLOSE_WAIT state.", e);
+              return;
+            }
{code}

Can we catch specific exceptions instead of {{Exception}}?

{code}
+
+    /**
+     * To close the stream's socket. HBASE-9393
+     */
+    void unbufferStream();
{code}

this doesn't need to reference the JIRA (both instances). Should specify that 
implementers should make it threadsafe (since we use it without locks in 
various places)

{code}
+    } finally {
+      fsdis.unbuffer();
     }
{code}

This call means that {{openReader}} can only be called within a lock for 
{{fsdis}}. The javadocs should say so. (do all uses already do this?)

{code}
@@ -543,7 +550,7 @@ public class HFile {
     } else {
       hfs = (HFileSystem)fs;
     }
-    return pickReaderVersion(path, fsdis, size, cacheConf, hfs, conf);
+    return openReader(path, fsdis, size, cacheConf, hfs, conf);
   }
{code}

This call means that {{createReader(FileSystem, Path, FSDataInputStreamWrapper, 
long, CacheConfig, Configuration)}} can only be called within a lock for fsdis, 
javadocs should say so. (do all uses already do this?)



> Hbase does not closing a closed socket resulting in many CLOSE_WAIT 
> --------------------------------------------------------------------
>
>                 Key: HBASE-9393
>                 URL: https://issues.apache.org/jira/browse/HBASE-9393
>             Project: HBase
>          Issue Type: Bug
>    Affects Versions: 0.94.2, 0.98.0
>         Environment: Centos 6.4 - 7 regionservers/datanodes, 8 TB per node, 
> 7279 regions
>            Reporter: Avi Zrachya
>            Assignee: Ashish Singhi
>            Priority: Critical
>             Fix For: 2.0.0
>
>         Attachments: HBASE-9393.patch, HBASE-9393.v1.patch, 
> HBASE-9393.v10.patch, HBASE-9393.v11.patch, HBASE-9393.v12.patch, 
> HBASE-9393.v13.patch, HBASE-9393.v14.patch, HBASE-9393.v2.patch, 
> HBASE-9393.v3.patch, HBASE-9393.v4.patch, HBASE-9393.v5.patch, 
> HBASE-9393.v5.patch, HBASE-9393.v5.patch, HBASE-9393.v6.patch, 
> HBASE-9393.v6.patch, HBASE-9393.v6.patch, HBASE-9393.v7.patch, 
> HBASE-9393.v8.patch, HBASE-9393.v9.patch
>
>
> HBase dose not close a dead connection with the datanode.
> This resulting in over 60K CLOSE_WAIT and at some point HBase can not connect 
> to the datanode because too many mapped sockets from one host to another on 
> the same port.
> The example below is with low CLOSE_WAIT count because we had to restart 
> hbase to solve the porblem, later in time it will incease to 60-100K sockets 
> on CLOSE_WAIT
> [root@hd2-region3 ~]# netstat -nap |grep CLOSE_WAIT |grep 21592 |wc -l
> 13156
> [root@hd2-region3 ~]# ps -ef |grep 21592
> root     17255 17219  0 12:26 pts/0    00:00:00 grep 21592
> hbase    21592     1 17 Aug29 ?        03:29:06 
> /usr/java/jdk1.6.0_26/bin/java -XX:OnOutOfMemoryError=kill -9 %p -Xmx8000m 
> -ea -XX:+UseConcMarkSweepGC -XX:+CMSIncrementalMode 
> -Dhbase.log.dir=/var/log/hbase 
> -Dhbase.log.file=hbase-hbase-regionserver-hd2-region3.swnet.corp.log ...



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