Hi,

I'm starting to give coprocessors a try, but I'm having trouble getting the
HBase cluster to start up properly after deploying the new configuration.
My coprocessor is trivial, but it is only to get my feet wet. I override
the prePut method to add the row being put into a table into another table
as well.

public class MyCustomRegionObserver extends BaseRegionObserver {

    public void prePut(final ObserverContext<RegionCoprocessorEnvironment>
e,
            final Put put, final WALEdit edit, boolean writeToWAL)
            throws IOException {
        HTableInterface hti e.getEnvironment().getTable(Bytes.toBytes("accesses"));
        try {
            hti.put(new Put(put.getRow()).add(Bytes.toBytes("num"),
                    Bytes.toBytes("value"), Bytes.toBytes(0)));
        } finally {
            hti.close();
        }
    }

}

I updated hbase-site.xml to reflect this coprocessor.

  <property>
    <name>hbase.coprocessor.region.classes</name>

<value>com.hbase.example.region.coprocessors.MyCustomRegionObserver</value>
  </property>

I update all the machines with the new configuration and I added the
coprocessor jar to /usr/lib/hbase/lib on each machine (I don't change the
default HBase classpath in hbase-env.sh)

When I restart my HBase cluster the cluster does not ever finish assigning
META region. In the master's log there are a lot of
NotServingRegionExceptions: Region is not online: .META.,,1. Other than
that I can't see any log messages that indicate any specific about loading
the coprocessor. If I then comment out the coprocessor property in
hbase-site.xml and restart the cluster, then HBase starts up fine.

I am new to coprocessors so any help is great.

Thanks.

Check this if it solves your problem :

http://helpmetocode.blogspot.in/2012/05/issueif-you-master-machines-region.html

On Fri, May 25, 2012 at 7:25 PM, Kevin <[EMAIL PROTECTED]> wrote:

> Hi,
>
> I'm starting to give coprocessors a try, but I'm having trouble getting the
> HBase cluster to start up properly after deploying the new configuration.
> My coprocessor is trivial, but it is only to get my feet wet. I override
> the prePut method to add the row being put into a table into another table
> as well.
>
> public class MyCustomRegionObserver extends BaseRegionObserver {
>
>    public void prePut(final ObserverContext<RegionCoprocessorEnvironment>
> e,
>            final Put put, final WALEdit edit, boolean writeToWAL)
>            throws IOException {
>        HTableInterface hti > e.getEnvironment().getTable(Bytes.toBytes("accesses"));
>        try {
>            hti.put(new Put(put.getRow()).add(Bytes.toBytes("num"),
>                    Bytes.toBytes("value"), Bytes.toBytes(0)));
>        } finally {
>            hti.close();
>        }
>    }
>
> }
>
> I updated hbase-site.xml to reflect this coprocessor.
>
>  <property>
>    <name>hbase.coprocessor.region.classes</name>
>
> <value>com.hbase.example.region.coprocessors.MyCustomRegionObserver</value>
>  </property>
>
> I update all the machines with the new configuration and I added the
> coprocessor jar to /usr/lib/hbase/lib on each machine (I don't change the
> default HBase classpath in hbase-env.sh)
>
> When I restart my HBase cluster the cluster does not ever finish assigning
> META region. In the master's log there are a lot of
> NotServingRegionExceptions: Region is not online: .META.,,1. Other than
> that I can't see any log messages that indicate any specific about loading
> the coprocessor. If I then comment out the coprocessor property in
> hbase-site.xml and restart the cluster, then HBase starts up fine.
>
> I am new to coprocessors so any help is great.
>
> Thanks.
>

--
∞
Shashwat Shriparv

I don't think my issue stems from clocks being out of sync. All my servers
are syncing to a NTP server. Checking the dates on each machine shows that
they differ far less than 30 seconds.

On Fri, May 25, 2012 at 10:00 AM, shashwat shriparv <
[EMAIL PROTECTED]> wrote:

> Check this if it solves your problem :
>
>
> http://helpmetocode.blogspot.in/2012/05/issueif-you-master-machines-region.html
>
>
>
> On Fri, May 25, 2012 at 7:25 PM, Kevin <[EMAIL PROTECTED]> wrote:
>
> > Hi,
> >
> > I'm starting to give coprocessors a try, but I'm having trouble getting
> the
> > HBase cluster to start up properly after deploying the new configuration.
> > My coprocessor is trivial, but it is only to get my feet wet. I override
> > the prePut method to add the row being put into a table into another
> table
> > as well.
> >
> > public class MyCustomRegionObserver extends BaseRegionObserver {
> >
> >    public void prePut(final ObserverContext<RegionCoprocessorEnvironment>
> > e,
> >            final Put put, final WALEdit edit, boolean writeToWAL)
> >            throws IOException {
> >        HTableInterface hti > > e.getEnvironment().getTable(Bytes.toBytes("accesses"));
> >        try {
> >            hti.put(new Put(put.getRow()).add(Bytes.toBytes("num"),
> >                    Bytes.toBytes("value"), Bytes.toBytes(0)));
> >        } finally {
> >            hti.close();
> >        }
> >    }
> >
> > }
> >
> > I updated hbase-site.xml to reflect this coprocessor.
> >
> >  <property>
> >    <name>hbase.coprocessor.region.classes</name>
> >
> >
> <value>com.hbase.example.region.coprocessors.MyCustomRegionObserver</value>
> >  </property>
> >
> > I update all the machines with the new configuration and I added the
> > coprocessor jar to /usr/lib/hbase/lib on each machine (I don't change the
> > default HBase classpath in hbase-env.sh)
> >
> > When I restart my HBase cluster the cluster does not ever finish
> assigning
> > META region. In the master's log there are a lot of
> > NotServingRegionExceptions: Region is not online: .META.,,1. Other than
> > that I can't see any log messages that indicate any specific about
> loading
> > the coprocessor. If I then comment out the coprocessor property in
> > hbase-site.xml and restart the cluster, then HBase starts up fine.
> >
> > I am new to coprocessors so any help is great.
> >
> > Thanks.
> >
>
>
>
> --
>
>
> ∞
> Shashwat Shriparv
>

> When I restart my HBase cluster the cluster does not ever finish assigning
> META region. In the master's log there are a lot of
> NotServingRegionExceptions: Region is not online: .META.,,1. Other than
> that I can't see any log messages that indicate any specific about loading
> the coprocessor. If I then comment out the coprocessor property in
> hbase-site.xml and restart the cluster, then HBase starts up fine.

In the future, check the regionserver logs. Why is META not able to deploy?

In this case, you should know that Observers installed as system
coprocessors, i.e. by way of site file properties like
hbase.coprocessor.region.classes, are also installed on the META
region. Your code is trying to find a user table via getTable before
META is deployed. That can't work. The exception generated fails the
open of the META region.

Best regards,

   - Andy

Problems worthy of attack prove their worth by hitting back. - Piet
Hein (via Tom White)

I didn't think about it like that. I just figured that HBase would block
certain components until the cluster is stable. However, like you said,
since I configured my Observer as a system coprocessor, your explanation
makes sense. I'll have to come up with another example. Thank you for your
answer and the great explanation.
On Fri, May 25, 2012 at 2:31 PM, Andrew Purtell <[EMAIL PROTECTED]> wrote:

> > When I restart my HBase cluster the cluster does not ever finish
> assigning
> > META region. In the master's log there are a lot of
> > NotServingRegionExceptions: Region is not online: .META.,,1. Other than
> > that I can't see any log messages that indicate any specific about
> loading
> > the coprocessor. If I then comment out the coprocessor property in
> > hbase-site.xml and restart the cluster, then HBase starts up fine.
>
> In the future, check the regionserver logs. Why is META not able to deploy?
>
> In this case, you should know that Observers installed as system
> coprocessors, i.e. by way of site file properties like
> hbase.coprocessor.region.classes, are also installed on the META
> region. Your code is trying to find a user table via getTable before
> META is deployed. That can't work. The exception generated fails the
> open of the META region.
>
> Best regards,
>
>    - Andy
>
> Problems worthy of attack prove their worth by hitting back. - Piet
> Hein (via Tom White)
>

Here is my SS:  259 71 2451

On May 25, 2012, at 11:31 AM, Andrew Purtell <[EMAIL PROTECTED]> wrote:

>> When I restart my HBase cluster the cluster does not ever finish assigning
>> META region. In the master's log there are a lot of
>> NotServingRegionExceptions: Region is not online: .META.,,1. Other than
>> that I can't see any log messages that indicate any specific about loading
>> the coprocessor. If I then comment out the coprocessor property in
>> hbase-site.xml and restart the cluster, then HBase starts up fine.
>
> In the future, check the regionserver logs. Why is META not able to deploy?
>
> In this case, you should know that Observers installed as system
> coprocessors, i.e. by way of site file properties like
> hbase.coprocessor.region.classes, are also installed on the META
> region. Your code is trying to find a user table via getTable before
> META is deployed. That can't work. The exception generated fails the
> open of the META region.
>
> Best regards,
>
>    - Andy
>
> Problems worthy of attack prove their worth by hitting back. - Piet
> Hein (via Tom White)

Hi Kevin

  <property>
    <name>hbase.coprocessor.region.classes</name>

<value>com.hbase.example.region.coprocessors.MyCustomRegionObserver</value>
  </property>

Instead of configuring the FQCN of your region observer against "hbase.coprocessor.region.classes", you can go with configuring the same against the config param "hbase.coprocessor.user.region.classes"

 <property>
    <name>hbase.coprocessor.user.region.classes</name>
    <value>com.hbase.example.region.coprocessors.MyCustomRegionObserver</value>
  </property>

This observer will not got called while dealing with ROOT and META table then...

-Anoop-
________________________________________
From: Kevin [[EMAIL PROTECTED]]
Sent: Friday, May 25, 2012 7:25 PM
To: [EMAIL PROTECTED]
Subject: Problems Loading RegionObserver Coprocessor

Hi,

I'm starting to give coprocessors a try, but I'm having trouble getting the
HBase cluster to start up properly after deploying the new configuration.
My coprocessor is trivial, but it is only to get my feet wet. I override
the prePut method to add the row being put into a table into another table
as well.

public class MyCustomRegionObserver extends BaseRegionObserver {

    public void prePut(final ObserverContext<RegionCoprocessorEnvironment>
e,
            final Put put, final WALEdit edit, boolean writeToWAL)
            throws IOException {
        HTableInterface hti e.getEnvironment().getTable(Bytes.toBytes("accesses"));
        try {
            hti.put(new Put(put.getRow()).add(Bytes.toBytes("num"),
                    Bytes.toBytes("value"), Bytes.toBytes(0)));
        } finally {
            hti.close();
        }
    }

}

I updated hbase-site.xml to reflect this coprocessor.

  <property>
    <name>hbase.coprocessor.region.classes</name>

<value>com.hbase.example.region.coprocessors.MyCustomRegionObserver</value>
  </property>

I update all the machines with the new configuration and I added the
coprocessor jar to /usr/lib/hbase/lib on each machine (I don't change the
default HBase classpath in hbase-env.sh)

When I restart my HBase cluster the cluster does not ever finish assigning
META region. In the master's log there are a lot of
NotServingRegionExceptions: Region is not online: .META.,,1. Other than
that I can't see any log messages that indicate any specific about loading
the coprocessor. If I then comment out the coprocessor property in
hbase-site.xml and restart the cluster, then HBase starts up fine.

I am new to coprocessors so any help is great.

Thanks.