UNOFFICIAL

It looks like an issue with one of the metadata table tablets. On startup the 
server that hosts a particular metadata tablet gets scanned by all other tablet 
servers in the cluster.  This then crashes that tablet server with an error in 
the tserver log;

... [zookeeper.ZooCache] WARN: Saw (possibly) transient exception communicating 
with ZooKeeper, will retry
SessionExpiredException: KeeperErrorCode = Session expired for 
/accumulo/4234234234234234/namespaces/+accumulo/conf/table.scan.max.memory

That metadata table tablet is then transferred to another host which then fails 
also, and so on.

While the server is hosting this metadata tablet, we see the following log 
statement from all tserver.logs in the cluster:

.... [impl.ThriftScanner] DEBUG: Scan failed, thrift error 
org.apache.thrift.transport.TTransportException  null 
(!0;1vm\\;125.323.233.23::2016103<,server.com.org:9997<http://server.com.org:9997/>,2342423df12341d)
Hope that helps complete the picture.


________________________________
From: Christopher [mailto:[email protected]]
Sent: Tuesday, 21 February 2017 13:17
To: [email protected]
Subject: Re: accumulo.root invalid table reference [SEC=UNOFFICIAL]


Removing them is probably a bad idea. The root table entries correspond to 
split points in the metadata table. There is no need for the tables which 
existed when the metadata table split to still exist for this to continue to 
act as a valid split point.

Would need to see the exception stack trace, or at least an error message, to 
troubleshoot the shell scanning error you saw.

On Mon, Feb 20, 2017, 20:00 Dickson, Matt MR 
<[email protected]<mailto:[email protected]>> wrote:
UNOFFICIAL

In case it is ok to remove these from the root table, how can I scan the root 
table for rows with a rowid starting with !0;1vm?

Running "scan -b !0;1vm" throws an exception and exits the shell.


-----Original Message-----
From: Dickson, Matt MR 
[mailto:[email protected]<mailto:[email protected]>]
Sent: Tuesday, 21 February 2017 09:30
To: '[email protected]<mailto:[email protected]>'
Subject: RE: accumulo.root invalid table reference [SEC=UNOFFICIAL]

UNOFFICIAL


Does that mean I should have entries for 1vm in the metadata table 
corresponding to the root table?

We are running 1.6.5


-----Original Message-----
From: Josh Elser [mailto:[email protected]<mailto:[email protected]>]
Sent: Tuesday, 21 February 2017 09:22
To: [email protected]<mailto:[email protected]>
Subject: Re: accumulo.root invalid table reference [SEC=UNOFFICIAL]

The root table should only reference the tablets in the metadata table.
It's a hierarchy: like metadata is for the user tables, root is for the 
metadata table.

What version are ya running, Matt?

Dickson, Matt MR wrote:
> *UNOFFICIAL*
>
> I have a situation where all tablet servers are progressively being
> declared dead. From the logs the tservers report errors like:
> 2017-02-.... DEBUG: Scan failed thrift error
> org.apache.thrift.trasport.TTransportException null
> (!0;1vm\\125.323.233.23::2016103<,server.com.org:9997<http://server.com.org:9997>,2342423df12341d)
> 1vm was a table id that was deleted several months ago so it appears
> there is some invalid reference somewhere.
> Scanning the metadata table "scan -b 1vm" returns no rows returned for 1vm.
> A scan of the accumulo.root table returns approximately 15 rows that
> start with; !0:1vm;<i/p addr>/::2016103 /blah/ // How are the root
> table entries used and would it be safe to remove these entries since
> they reference a deleted table?
> Thanks in advance,
> Matt
> //
--
Christopher

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