[jira] [Updated] (HBASE-13960) HConnection stuck with UnknownHostException

["Yu Li (JIRA)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/HBASE-13960?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Yu Li updated HBASE-13960:
--------------------------
    Attachment: HBASE-13960-update.patch

The updated patch. Main changes include:
1. Make it compile with latest code base
2. Remove some unnecessary codes
3. Do necessary renaming to improve readability

[~ykt836], please let me know if it's ok that I take over this task, thanks.

> HConnection stuck with UnknownHostException 
> --------------------------------------------
>
>                 Key: HBASE-13960
>                 URL: https://issues.apache.org/jira/browse/HBASE-13960
>             Project: HBase
>          Issue Type: Bug
>          Components: hbase
>    Affects Versions: 0.98.8
>            Reporter: Kurt Young
>         Attachments: HBASE-13960-0.98-v1.patch, HBASE-13960-update.patch, HBASE-13960-v2.patch
>
>
> when put/get from hbase, if we meet a temporary dns failure causes resolve RS's host, the error will never recovered. put/get will failed with UnknownHostException forever. 
> I checked the code, and the reason maybe:
> 1. when RegionServerCallable or MultiServerCallable prepare(), it gets a  ClientService.BlockingInterface stub from Hconnection
> 2. In HConnectionImplementation::getClient, it caches the stub with a BlockingRpcChannelImplementation
> 3. In BlockingRpcChannelImplementation(), 
>      this.isa = new InetSocketAddress(sn.getHostname(), sn.getPort()); If we meet a  temporary dns failure then the "address" in isa will be null.
> 4. then we launch the real rpc call, the following stack is:
> Caused by: java.net.UnknownHostException: unknown host: xxx.host2
> 	at org.apache.hadoop.hbase.ipc.RpcClient$Connection.<init>(RpcClient.java:385)
> 	at org.apache.hadoop.hbase.ipc.RpcClient.createConnection(RpcClient.java:351)
> 	at org.apache.hadoop.hbase.ipc.RpcClient.getConnection(RpcClient.java:1523)
> 	at org.apache.hadoop.hbase.ipc.RpcClient.call(RpcClient.java:1435)
> 	at org.apache.hadoop.hbase.ipc.RpcClient.callBlockingMethod(RpcClient.java:1654)
> 	at org.apache.hadoop.hbase.ipc.RpcClient$BlockingRpcChannelImplementation.callBlockingMethod(RpcClient.java:1712)
> Besides, i noticed there is a protection in RpcClient:
> if (remoteId.getAddress().isUnresolved()) {
>         throw new UnknownHostException("unknown host: " + remoteId.getAddress().getHostName());
>       }
> shouldn't we do something when this situation occurred? 



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)