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Posted to user@hbase.apache.org by Ted Yu <yu...@gmail.com> on 2010/01/15 19:22:57 UTC
HBaseAdmin and ConcurrentModificationException
Hi,
We use hbase-0.20.1
I have seen this randomly fail with a ConcurrentModificationException:
HBaseAdmin admin = new HBaseAdmin(hbaseConf);
Has anybody else seen this behavior ?
Thanks
Re: HBaseAdmin and ConcurrentModificationException
Posted by stack <st...@duboce.net>.
Don't make changes to the Configuration in your JVM after its been shared
amongst threads? Configuration is not thread safe. It'd be tough making it
thread-safe. It comes from hadoop-common.
St.Ack
On Fri, Jan 15, 2010 at 11:14 AM, Ted Yu <yu...@gmail.com> wrote:
> Here is the stack:
> INFO | jvm 1 | 2010/01/14 16:03:11 |
> java.util.ConcurrentModificationException
> INFO | jvm 1 | 2010/01/14 16:03:11 | at
> java.util.AbstractList$Itr.checkForComodification(Unknown Source)
> INFO | jvm 1 | 2010/01/14 16:03:11 | at
> java.util.AbstractList$Itr.next(Unknown Source)
> INFO | jvm 1 | 2010/01/14 16:03:11 | at
> org.apache.hadoop.conf.Configuration.loadResources(Configuration.java:1028)
> INFO | jvm 1 | 2010/01/14 16:03:11 | at
> org.apache.hadoop.conf.Configuration.getProps(Configuration.java:979)
> INFO | jvm 1 | 2010/01/14 16:03:11 | at
> org.apache.hadoop.conf.Configuration.get(Configuration.java:435)
> INFO | jvm 1 | 2010/01/14 16:03:11 | at
> org.apache.hadoop.hbase.client.HConnectionManager
> $TableServers.<init>(HConnectionManager.java:257)
> INFO | jvm 1 | 2010/01/14 16:03:11 | at
>
> org.apache.hadoop.hbase.client.HConnectionManager.getConnection(HConnectionManager.java:99)
> INFO | jvm 1 | 2010/01/14 16:03:11 | at
> org.apache.hadoop.hbase.client.HBaseAdmin.<init>(HBaseAdmin.java:68)
>
> This line in HConnectionManager caused the exception:
> String serverClassName =
> conf.get(REGION_SERVER_CLASS, DEFAULT_REGION_SERVER_CLASS);
>
> Strangely, reading config file threw ConcurrentModificationException:
> "Z:\kindsight\hbase\software\conf\hbase-default.xml"(117,11):
> <name>hbase.regionserver.class</name>
>
> Please advise.
>
> On Fri, Jan 15, 2010 at 10:28 AM, stack <st...@duboce.net> wrote:
>
> > You have multiple instances of HBaseAdmin floating around? If so, why?
> > Please paste full stack trace. That'd help.
> > Yours,
> > St.Ack
> >
> > On Fri, Jan 15, 2010 at 10:22 AM, Ted Yu <yu...@gmail.com> wrote:
> >
> > > Hi,
> > > We use hbase-0.20.1
> > > I have seen this randomly fail with a ConcurrentModificationException:
> > > HBaseAdmin admin = new HBaseAdmin(hbaseConf);
> > >
> > > Has anybody else seen this behavior ?
> > >
> > > Thanks
> > >
> >
>
Re: HBaseAdmin and ConcurrentModificationException
Posted by Ted Yu <yu...@gmail.com>.
Here is the stack:
INFO | jvm 1 | 2010/01/14 16:03:11 |
java.util.ConcurrentModificationException
INFO | jvm 1 | 2010/01/14 16:03:11 | at
java.util.AbstractList$Itr.checkForComodification(Unknown Source)
INFO | jvm 1 | 2010/01/14 16:03:11 | at
java.util.AbstractList$Itr.next(Unknown Source)
INFO | jvm 1 | 2010/01/14 16:03:11 | at
org.apache.hadoop.conf.Configuration.loadResources(Configuration.java:1028)
INFO | jvm 1 | 2010/01/14 16:03:11 | at
org.apache.hadoop.conf.Configuration.getProps(Configuration.java:979)
INFO | jvm 1 | 2010/01/14 16:03:11 | at
org.apache.hadoop.conf.Configuration.get(Configuration.java:435)
INFO | jvm 1 | 2010/01/14 16:03:11 | at
org.apache.hadoop.hbase.client.HConnectionManager
$TableServers.<init>(HConnectionManager.java:257)
INFO | jvm 1 | 2010/01/14 16:03:11 | at
org.apache.hadoop.hbase.client.HConnectionManager.getConnection(HConnectionManager.java:99)
INFO | jvm 1 | 2010/01/14 16:03:11 | at
org.apache.hadoop.hbase.client.HBaseAdmin.<init>(HBaseAdmin.java:68)
This line in HConnectionManager caused the exception:
String serverClassName =
conf.get(REGION_SERVER_CLASS, DEFAULT_REGION_SERVER_CLASS);
Strangely, reading config file threw ConcurrentModificationException:
"Z:\kindsight\hbase\software\conf\hbase-default.xml"(117,11):
<name>hbase.regionserver.class</name>
Please advise.
On Fri, Jan 15, 2010 at 10:28 AM, stack <st...@duboce.net> wrote:
> You have multiple instances of HBaseAdmin floating around? If so, why?
> Please paste full stack trace. That'd help.
> Yours,
> St.Ack
>
> On Fri, Jan 15, 2010 at 10:22 AM, Ted Yu <yu...@gmail.com> wrote:
>
> > Hi,
> > We use hbase-0.20.1
> > I have seen this randomly fail with a ConcurrentModificationException:
> > HBaseAdmin admin = new HBaseAdmin(hbaseConf);
> >
> > Has anybody else seen this behavior ?
> >
> > Thanks
> >
>
Re: HBaseAdmin and ConcurrentModificationException
Posted by stack <st...@duboce.net>.
You have multiple instances of HBaseAdmin floating around? If so, why?
Please paste full stack trace. That'd help.
Yours,
St.Ack
On Fri, Jan 15, 2010 at 10:22 AM, Ted Yu <yu...@gmail.com> wrote:
> Hi,
> We use hbase-0.20.1
> I have seen this randomly fail with a ConcurrentModificationException:
> HBaseAdmin admin = new HBaseAdmin(hbaseConf);
>
> Has anybody else seen this behavior ?
>
> Thanks
>