You are viewing a plain text version of this content. The canonical link for it is here.
Posted to user@hbase.apache.org by Al Lias <al...@gmx.de> on 2010/03/31 13:38:12 UTC
Is NotServingRegionException really an Exception?
As I do see this Exception really often in our logs. I wonder if this
indicates a regular thing (within splits etc) or if this is something
that should not normally happen.
I see it often in Jira as a reason for something else that fails, but
for a regular client request, where the client not perfectly up-to-date
with region information it looks as something normal. Am I right here?
Al
Re: Is NotServingRegionException really an Exception?
Posted by Ryan Rawson <ry...@gmail.com>.
I think the time to fix all these wire-level API stuff is when we
rework to use avro. In the mean time it would be a very disturbing
change alas.
-ryan
On Wed, Mar 31, 2010 at 6:35 PM, Yabo Xu <ar...@gmail.com> wrote:
> Thanks, J-D. I will do it next time I catch this.
>
> Best,
> Arber
>
> On Thu, Apr 1, 2010 at 12:56 AM, Jean-Daniel Cryans <jd...@apache.org>wrote:
>
>> Arber,
>>
>> If your cluster doesn't recover, it means there's something else going
>> on. Feel free to start a new thread on this mailing list to discuss
>> that, posting relevant informations like version, hardware,
>> configurations and logs.
>>
>> J-D
>>
>> On Wed, Mar 31, 2010 at 9:39 AM, Yabo Xu <ar...@gmail.com> wrote:
>> > Sorry for interrupting the thread. We also gets the annoying
>> > NotServingRegionException once in a while ( especially after intensive
>> > writing), and if it happens, it seems that the only way is to stop all
>> the
>> > programs and restart HBase.
>> >
>> > Any better way to deal with it? ( I tried flush operation on the shell,
>> but
>> > it does not work )
>> >
>> > Or how to avoid this from happening?
>> >
>> > Thanks,
>> > Arber
>> >
>> > On Wed, Mar 31, 2010 at 11:44 PM, Stack <st...@duboce.net> wrote:
>> >
>> >> I always thought that the throwing of an exception to signal moved
>> >> region was broke if only for the reason that it disturbing to new
>> >> users. See https://issues.apache.org/jira/browse/HBASE-72
>> >>
>> >> Would be nice to change it. I don't think it easy though. We'd need
>> >> to rig the RPC so calls were enveloped or some such so we could pass
>> >> status messages along with (or instead of) a query results.
>> >>
>> >> St.Ack
>> >>
>> >>
>> >> On Wed, Mar 31, 2010 at 8:06 AM, Edward Capriolo <edlinuxguru@gmail.com
>> >
>> >> wrote:
>> >> > On Wed, Mar 31, 2010 at 11:02 AM, Gary Helmling <gh...@gmail.com>
>> >> wrote:
>> >> >
>> >> >> Well I would still view it as an exceptional condition. The client
>> >> asked
>> >> >> for data back from a server that does not own that data. Sending
>> back
>> >> an
>> >> >> exception seems like the appropriate response, to me at least. It's
>> >> just
>> >> >> an
>> >> >> exceptional condition that's allowed to happen in favor of the
>> >> optimization
>> >> >> of caching region locations in memory on the client.
>> >> >>
>> >> >> I could see the reporting of the exception being misleading though if
>> >> it's
>> >> >> being logged at an error or warn level when it's a normal part of
>> >> >> operations. What's the logging level of the messages?
>> >> >>
>> >> >>
>> >> >> On Wed, Mar 31, 2010 at 10:51 AM, Al Lias <al...@gmx.de> wrote:
>> >> >>
>> >> >> > Am 31.03.2010 16:47, schrieb Gary Helmling:
>> >> >> > > NotServingRegionException is a normal part of operations when
>> >> regions
>> >> >> > > transition (ie due to splits). It's how the region server
>> signals
>> >> back
>> >> >> > to
>> >> >> > > the client that it needs to re-lookup the region location in
>> .META.
>> >> >> > (which
>> >> >> > > is normally cached in memory by the client, so can become stale).
>> >> >> > >
>> >> >> > > I'm sure it can also show up as a symptom of other problems, but
>> if
>> >> >> > you're
>> >> >> > > not seeing any other issues, then it's nothing to be concerned
>> >> about.
>> >> >> > >
>> >> >> >
>> >> >> > Thx Gary,
>> >> >> >
>> >> >> > this is my point: I see this many times in the (production)
>> >> logs
>> >> >> > when
>> >> >> > it is actually nothing to worry about. Should'nt this rather be a
>> >> normal
>> >> >> > response of a region server, instead an Exception?
>> >> >> >
>> >> >> > Al
>> >> >> >
>> >> >> > >
>> >> >> > > On Wed, Mar 31, 2010 at 7:38 AM, Al Lias <al...@gmx.de> wrote:
>> >> >> > >
>> >> >> > >> As I do see this Exception really often in our logs. I wonder if
>> >> this
>> >> >> > >> indicates a regular thing (within splits etc) or if this is
>> >> something
>> >> >> > >> that should not normally happen.
>> >> >> > >>
>> >> >> > >> I see it often in Jira as a reason for something else that
>> fails,
>> >> but
>> >> >> > >> for a regular client request, where the client not perfectly
>> >> >> up-to-date
>> >> >> > >> with region information it looks as something normal. Am I right
>> >> here?
>> >> >> > >>
>> >> >> > >>
>> >> >> > >> Al
>> >> >> > >>
>> >> >> > >
>> >> >> >
>> >> >> >
>> >> >>
>> >> > The LDAP api's throw a ReferralException when you try to update a read
>> >> only
>> >> > slave, so heir is a precedence for that. But true that an exception
>> may
>> >> be
>> >> > strong for something that is technically a warning.
>> >> >
>> >>
>> >
>>
>
Re: Is NotServingRegionException really an Exception?
Posted by Yabo Xu <ar...@gmail.com>.
Thanks, J-D. I will do it next time I catch this.
Best,
Arber
On Thu, Apr 1, 2010 at 12:56 AM, Jean-Daniel Cryans <jd...@apache.org>wrote:
> Arber,
>
> If your cluster doesn't recover, it means there's something else going
> on. Feel free to start a new thread on this mailing list to discuss
> that, posting relevant informations like version, hardware,
> configurations and logs.
>
> J-D
>
> On Wed, Mar 31, 2010 at 9:39 AM, Yabo Xu <ar...@gmail.com> wrote:
> > Sorry for interrupting the thread. We also gets the annoying
> > NotServingRegionException once in a while ( especially after intensive
> > writing), and if it happens, it seems that the only way is to stop all
> the
> > programs and restart HBase.
> >
> > Any better way to deal with it? ( I tried flush operation on the shell,
> but
> > it does not work )
> >
> > Or how to avoid this from happening?
> >
> > Thanks,
> > Arber
> >
> > On Wed, Mar 31, 2010 at 11:44 PM, Stack <st...@duboce.net> wrote:
> >
> >> I always thought that the throwing of an exception to signal moved
> >> region was broke if only for the reason that it disturbing to new
> >> users. See https://issues.apache.org/jira/browse/HBASE-72
> >>
> >> Would be nice to change it. I don't think it easy though. We'd need
> >> to rig the RPC so calls were enveloped or some such so we could pass
> >> status messages along with (or instead of) a query results.
> >>
> >> St.Ack
> >>
> >>
> >> On Wed, Mar 31, 2010 at 8:06 AM, Edward Capriolo <edlinuxguru@gmail.com
> >
> >> wrote:
> >> > On Wed, Mar 31, 2010 at 11:02 AM, Gary Helmling <gh...@gmail.com>
> >> wrote:
> >> >
> >> >> Well I would still view it as an exceptional condition. The client
> >> asked
> >> >> for data back from a server that does not own that data. Sending
> back
> >> an
> >> >> exception seems like the appropriate response, to me at least. It's
> >> just
> >> >> an
> >> >> exceptional condition that's allowed to happen in favor of the
> >> optimization
> >> >> of caching region locations in memory on the client.
> >> >>
> >> >> I could see the reporting of the exception being misleading though if
> >> it's
> >> >> being logged at an error or warn level when it's a normal part of
> >> >> operations. What's the logging level of the messages?
> >> >>
> >> >>
> >> >> On Wed, Mar 31, 2010 at 10:51 AM, Al Lias <al...@gmx.de> wrote:
> >> >>
> >> >> > Am 31.03.2010 16:47, schrieb Gary Helmling:
> >> >> > > NotServingRegionException is a normal part of operations when
> >> regions
> >> >> > > transition (ie due to splits). It's how the region server
> signals
> >> back
> >> >> > to
> >> >> > > the client that it needs to re-lookup the region location in
> .META.
> >> >> > (which
> >> >> > > is normally cached in memory by the client, so can become stale).
> >> >> > >
> >> >> > > I'm sure it can also show up as a symptom of other problems, but
> if
> >> >> > you're
> >> >> > > not seeing any other issues, then it's nothing to be concerned
> >> about.
> >> >> > >
> >> >> >
> >> >> > Thx Gary,
> >> >> >
> >> >> > this is my point: I see this many times in the (production)
> >> logs
> >> >> > when
> >> >> > it is actually nothing to worry about. Should'nt this rather be a
> >> normal
> >> >> > response of a region server, instead an Exception?
> >> >> >
> >> >> > Al
> >> >> >
> >> >> > >
> >> >> > > On Wed, Mar 31, 2010 at 7:38 AM, Al Lias <al...@gmx.de> wrote:
> >> >> > >
> >> >> > >> As I do see this Exception really often in our logs. I wonder if
> >> this
> >> >> > >> indicates a regular thing (within splits etc) or if this is
> >> something
> >> >> > >> that should not normally happen.
> >> >> > >>
> >> >> > >> I see it often in Jira as a reason for something else that
> fails,
> >> but
> >> >> > >> for a regular client request, where the client not perfectly
> >> >> up-to-date
> >> >> > >> with region information it looks as something normal. Am I right
> >> here?
> >> >> > >>
> >> >> > >>
> >> >> > >> Al
> >> >> > >>
> >> >> > >
> >> >> >
> >> >> >
> >> >>
> >> > The LDAP api's throw a ReferralException when you try to update a read
> >> only
> >> > slave, so heir is a precedence for that. But true that an exception
> may
> >> be
> >> > strong for something that is technically a warning.
> >> >
> >>
> >
>
Re: Is NotServingRegionException really an Exception?
Posted by Jean-Daniel Cryans <jd...@apache.org>.
Arber,
If your cluster doesn't recover, it means there's something else going
on. Feel free to start a new thread on this mailing list to discuss
that, posting relevant informations like version, hardware,
configurations and logs.
J-D
On Wed, Mar 31, 2010 at 9:39 AM, Yabo Xu <ar...@gmail.com> wrote:
> Sorry for interrupting the thread. We also gets the annoying
> NotServingRegionException once in a while ( especially after intensive
> writing), and if it happens, it seems that the only way is to stop all the
> programs and restart HBase.
>
> Any better way to deal with it? ( I tried flush operation on the shell, but
> it does not work )
>
> Or how to avoid this from happening?
>
> Thanks,
> Arber
>
> On Wed, Mar 31, 2010 at 11:44 PM, Stack <st...@duboce.net> wrote:
>
>> I always thought that the throwing of an exception to signal moved
>> region was broke if only for the reason that it disturbing to new
>> users. See https://issues.apache.org/jira/browse/HBASE-72
>>
>> Would be nice to change it. I don't think it easy though. We'd need
>> to rig the RPC so calls were enveloped or some such so we could pass
>> status messages along with (or instead of) a query results.
>>
>> St.Ack
>>
>>
>> On Wed, Mar 31, 2010 at 8:06 AM, Edward Capriolo <ed...@gmail.com>
>> wrote:
>> > On Wed, Mar 31, 2010 at 11:02 AM, Gary Helmling <gh...@gmail.com>
>> wrote:
>> >
>> >> Well I would still view it as an exceptional condition. The client
>> asked
>> >> for data back from a server that does not own that data. Sending back
>> an
>> >> exception seems like the appropriate response, to me at least. It's
>> just
>> >> an
>> >> exceptional condition that's allowed to happen in favor of the
>> optimization
>> >> of caching region locations in memory on the client.
>> >>
>> >> I could see the reporting of the exception being misleading though if
>> it's
>> >> being logged at an error or warn level when it's a normal part of
>> >> operations. What's the logging level of the messages?
>> >>
>> >>
>> >> On Wed, Mar 31, 2010 at 10:51 AM, Al Lias <al...@gmx.de> wrote:
>> >>
>> >> > Am 31.03.2010 16:47, schrieb Gary Helmling:
>> >> > > NotServingRegionException is a normal part of operations when
>> regions
>> >> > > transition (ie due to splits). It's how the region server signals
>> back
>> >> > to
>> >> > > the client that it needs to re-lookup the region location in .META.
>> >> > (which
>> >> > > is normally cached in memory by the client, so can become stale).
>> >> > >
>> >> > > I'm sure it can also show up as a symptom of other problems, but if
>> >> > you're
>> >> > > not seeing any other issues, then it's nothing to be concerned
>> about.
>> >> > >
>> >> >
>> >> > Thx Gary,
>> >> >
>> >> > this is my point: I see this many times in the (production)
>> logs
>> >> > when
>> >> > it is actually nothing to worry about. Should'nt this rather be a
>> normal
>> >> > response of a region server, instead an Exception?
>> >> >
>> >> > Al
>> >> >
>> >> > >
>> >> > > On Wed, Mar 31, 2010 at 7:38 AM, Al Lias <al...@gmx.de> wrote:
>> >> > >
>> >> > >> As I do see this Exception really often in our logs. I wonder if
>> this
>> >> > >> indicates a regular thing (within splits etc) or if this is
>> something
>> >> > >> that should not normally happen.
>> >> > >>
>> >> > >> I see it often in Jira as a reason for something else that fails,
>> but
>> >> > >> for a regular client request, where the client not perfectly
>> >> up-to-date
>> >> > >> with region information it looks as something normal. Am I right
>> here?
>> >> > >>
>> >> > >>
>> >> > >> Al
>> >> > >>
>> >> > >
>> >> >
>> >> >
>> >>
>> > The LDAP api's throw a ReferralException when you try to update a read
>> only
>> > slave, so heir is a precedence for that. But true that an exception may
>> be
>> > strong for something that is technically a warning.
>> >
>>
>
Re: Is NotServingRegionException really an Exception?
Posted by Yabo Xu <ar...@gmail.com>.
Sorry for interrupting the thread. We also gets the annoying
NotServingRegionException once in a while ( especially after intensive
writing), and if it happens, it seems that the only way is to stop all the
programs and restart HBase.
Any better way to deal with it? ( I tried flush operation on the shell, but
it does not work )
Or how to avoid this from happening?
Thanks,
Arber
On Wed, Mar 31, 2010 at 11:44 PM, Stack <st...@duboce.net> wrote:
> I always thought that the throwing of an exception to signal moved
> region was broke if only for the reason that it disturbing to new
> users. See https://issues.apache.org/jira/browse/HBASE-72
>
> Would be nice to change it. I don't think it easy though. We'd need
> to rig the RPC so calls were enveloped or some such so we could pass
> status messages along with (or instead of) a query results.
>
> St.Ack
>
>
> On Wed, Mar 31, 2010 at 8:06 AM, Edward Capriolo <ed...@gmail.com>
> wrote:
> > On Wed, Mar 31, 2010 at 11:02 AM, Gary Helmling <gh...@gmail.com>
> wrote:
> >
> >> Well I would still view it as an exceptional condition. The client
> asked
> >> for data back from a server that does not own that data. Sending back
> an
> >> exception seems like the appropriate response, to me at least. It's
> just
> >> an
> >> exceptional condition that's allowed to happen in favor of the
> optimization
> >> of caching region locations in memory on the client.
> >>
> >> I could see the reporting of the exception being misleading though if
> it's
> >> being logged at an error or warn level when it's a normal part of
> >> operations. What's the logging level of the messages?
> >>
> >>
> >> On Wed, Mar 31, 2010 at 10:51 AM, Al Lias <al...@gmx.de> wrote:
> >>
> >> > Am 31.03.2010 16:47, schrieb Gary Helmling:
> >> > > NotServingRegionException is a normal part of operations when
> regions
> >> > > transition (ie due to splits). It's how the region server signals
> back
> >> > to
> >> > > the client that it needs to re-lookup the region location in .META.
> >> > (which
> >> > > is normally cached in memory by the client, so can become stale).
> >> > >
> >> > > I'm sure it can also show up as a symptom of other problems, but if
> >> > you're
> >> > > not seeing any other issues, then it's nothing to be concerned
> about.
> >> > >
> >> >
> >> > Thx Gary,
> >> >
> >> > this is my point: I see this many times in the (production)
> logs
> >> > when
> >> > it is actually nothing to worry about. Should'nt this rather be a
> normal
> >> > response of a region server, instead an Exception?
> >> >
> >> > Al
> >> >
> >> > >
> >> > > On Wed, Mar 31, 2010 at 7:38 AM, Al Lias <al...@gmx.de> wrote:
> >> > >
> >> > >> As I do see this Exception really often in our logs. I wonder if
> this
> >> > >> indicates a regular thing (within splits etc) or if this is
> something
> >> > >> that should not normally happen.
> >> > >>
> >> > >> I see it often in Jira as a reason for something else that fails,
> but
> >> > >> for a regular client request, where the client not perfectly
> >> up-to-date
> >> > >> with region information it looks as something normal. Am I right
> here?
> >> > >>
> >> > >>
> >> > >> Al
> >> > >>
> >> > >
> >> >
> >> >
> >>
> > The LDAP api's throw a ReferralException when you try to update a read
> only
> > slave, so heir is a precedence for that. But true that an exception may
> be
> > strong for something that is technically a warning.
> >
>
Re: Is NotServingRegionException really an Exception?
Posted by Stack <st...@duboce.net>.
I always thought that the throwing of an exception to signal moved
region was broke if only for the reason that it disturbing to new
users. See https://issues.apache.org/jira/browse/HBASE-72
Would be nice to change it. I don't think it easy though. We'd need
to rig the RPC so calls were enveloped or some such so we could pass
status messages along with (or instead of) a query results.
St.Ack
On Wed, Mar 31, 2010 at 8:06 AM, Edward Capriolo <ed...@gmail.com> wrote:
> On Wed, Mar 31, 2010 at 11:02 AM, Gary Helmling <gh...@gmail.com> wrote:
>
>> Well I would still view it as an exceptional condition. The client asked
>> for data back from a server that does not own that data. Sending back an
>> exception seems like the appropriate response, to me at least. It's just
>> an
>> exceptional condition that's allowed to happen in favor of the optimization
>> of caching region locations in memory on the client.
>>
>> I could see the reporting of the exception being misleading though if it's
>> being logged at an error or warn level when it's a normal part of
>> operations. What's the logging level of the messages?
>>
>>
>> On Wed, Mar 31, 2010 at 10:51 AM, Al Lias <al...@gmx.de> wrote:
>>
>> > Am 31.03.2010 16:47, schrieb Gary Helmling:
>> > > NotServingRegionException is a normal part of operations when regions
>> > > transition (ie due to splits). It's how the region server signals back
>> > to
>> > > the client that it needs to re-lookup the region location in .META.
>> > (which
>> > > is normally cached in memory by the client, so can become stale).
>> > >
>> > > I'm sure it can also show up as a symptom of other problems, but if
>> > you're
>> > > not seeing any other issues, then it's nothing to be concerned about.
>> > >
>> >
>> > Thx Gary,
>> >
>> > this is my point: I see this many times in the (production) logs
>> > when
>> > it is actually nothing to worry about. Should'nt this rather be a normal
>> > response of a region server, instead an Exception?
>> >
>> > Al
>> >
>> > >
>> > > On Wed, Mar 31, 2010 at 7:38 AM, Al Lias <al...@gmx.de> wrote:
>> > >
>> > >> As I do see this Exception really often in our logs. I wonder if this
>> > >> indicates a regular thing (within splits etc) or if this is something
>> > >> that should not normally happen.
>> > >>
>> > >> I see it often in Jira as a reason for something else that fails, but
>> > >> for a regular client request, where the client not perfectly
>> up-to-date
>> > >> with region information it looks as something normal. Am I right here?
>> > >>
>> > >>
>> > >> Al
>> > >>
>> > >
>> >
>> >
>>
> The LDAP api's throw a ReferralException when you try to update a read only
> slave, so heir is a precedence for that. But true that an exception may be
> strong for something that is technically a warning.
>
Re: Is NotServingRegionException really an Exception?
Posted by Edward Capriolo <ed...@gmail.com>.
On Wed, Mar 31, 2010 at 11:02 AM, Gary Helmling <gh...@gmail.com> wrote:
> Well I would still view it as an exceptional condition. The client asked
> for data back from a server that does not own that data. Sending back an
> exception seems like the appropriate response, to me at least. It's just
> an
> exceptional condition that's allowed to happen in favor of the optimization
> of caching region locations in memory on the client.
>
> I could see the reporting of the exception being misleading though if it's
> being logged at an error or warn level when it's a normal part of
> operations. What's the logging level of the messages?
>
>
> On Wed, Mar 31, 2010 at 10:51 AM, Al Lias <al...@gmx.de> wrote:
>
> > Am 31.03.2010 16:47, schrieb Gary Helmling:
> > > NotServingRegionException is a normal part of operations when regions
> > > transition (ie due to splits). It's how the region server signals back
> > to
> > > the client that it needs to re-lookup the region location in .META.
> > (which
> > > is normally cached in memory by the client, so can become stale).
> > >
> > > I'm sure it can also show up as a symptom of other problems, but if
> > you're
> > > not seeing any other issues, then it's nothing to be concerned about.
> > >
> >
> > Thx Gary,
> >
> > this is my point: I see this many times in the (production) logs
> > when
> > it is actually nothing to worry about. Should'nt this rather be a normal
> > response of a region server, instead an Exception?
> >
> > Al
> >
> > >
> > > On Wed, Mar 31, 2010 at 7:38 AM, Al Lias <al...@gmx.de> wrote:
> > >
> > >> As I do see this Exception really often in our logs. I wonder if this
> > >> indicates a regular thing (within splits etc) or if this is something
> > >> that should not normally happen.
> > >>
> > >> I see it often in Jira as a reason for something else that fails, but
> > >> for a regular client request, where the client not perfectly
> up-to-date
> > >> with region information it looks as something normal. Am I right here?
> > >>
> > >>
> > >> Al
> > >>
> > >
> >
> >
>
The LDAP api's throw a ReferralException when you try to update a read only
slave, so heir is a precedence for that. But true that an exception may be
strong for something that is technically a warning.
Re: Is NotServingRegionException really an Exception?
Posted by Gary Helmling <gh...@gmail.com>.
Well I would still view it as an exceptional condition. The client asked
for data back from a server that does not own that data. Sending back an
exception seems like the appropriate response, to me at least. It's just an
exceptional condition that's allowed to happen in favor of the optimization
of caching region locations in memory on the client.
I could see the reporting of the exception being misleading though if it's
being logged at an error or warn level when it's a normal part of
operations. What's the logging level of the messages?
On Wed, Mar 31, 2010 at 10:51 AM, Al Lias <al...@gmx.de> wrote:
> Am 31.03.2010 16:47, schrieb Gary Helmling:
> > NotServingRegionException is a normal part of operations when regions
> > transition (ie due to splits). It's how the region server signals back
> to
> > the client that it needs to re-lookup the region location in .META.
> (which
> > is normally cached in memory by the client, so can become stale).
> >
> > I'm sure it can also show up as a symptom of other problems, but if
> you're
> > not seeing any other issues, then it's nothing to be concerned about.
> >
>
> Thx Gary,
>
> this is my point: I see this many times in the (production) logs
> when
> it is actually nothing to worry about. Should'nt this rather be a normal
> response of a region server, instead an Exception?
>
> Al
>
> >
> > On Wed, Mar 31, 2010 at 7:38 AM, Al Lias <al...@gmx.de> wrote:
> >
> >> As I do see this Exception really often in our logs. I wonder if this
> >> indicates a regular thing (within splits etc) or if this is something
> >> that should not normally happen.
> >>
> >> I see it often in Jira as a reason for something else that fails, but
> >> for a regular client request, where the client not perfectly up-to-date
> >> with region information it looks as something normal. Am I right here?
> >>
> >>
> >> Al
> >>
> >
>
>
Re: Is NotServingRegionException really an Exception?
Posted by Edward Capriolo <ed...@gmail.com>.
On Wed, Mar 31, 2010 at 10:51 AM, Al Lias <al...@gmx.de> wrote:
> Am 31.03.2010 16:47, schrieb Gary Helmling:
> > NotServingRegionException is a normal part of operations when regions
> > transition (ie due to splits). It's how the region server signals back
> to
> > the client that it needs to re-lookup the region location in .META.
> (which
> > is normally cached in memory by the client, so can become stale).
> >
> > I'm sure it can also show up as a symptom of other problems, but if
> you're
> > not seeing any other issues, then it's nothing to be concerned about.
> >
>
> Thx Gary,
>
> this is my point: I see this many times in the (production) logs
> when
> it is actually nothing to worry about. Should'nt this rather be a normal
> response of a region server, instead an Exception?
>
> Al
>
> >
> > On Wed, Mar 31, 2010 at 7:38 AM, Al Lias <al...@gmx.de> wrote:
> >
> >> As I do see this Exception really often in our logs. I wonder if this
> >> indicates a regular thing (within splits etc) or if this is something
> >> that should not normally happen.
> >>
> >> I see it often in Jira as a reason for something else that fails, but
> >> for a regular client request, where the client not perfectly up-to-date
> >> with region information it looks as something normal. Am I right here?
> >>
> >>
> >> Al
> >>
> >
>
>
Taking exceptions out from logs would be a nice thing. I would open up a
jira and/or submit a patch. I am sure no one will object to that.
Re: Is NotServingRegionException really an Exception?
Posted by Al Lias <al...@gmx.de>.
Am 31.03.2010 16:47, schrieb Gary Helmling:
> NotServingRegionException is a normal part of operations when regions
> transition (ie due to splits). It's how the region server signals back to
> the client that it needs to re-lookup the region location in .META. (which
> is normally cached in memory by the client, so can become stale).
>
> I'm sure it can also show up as a symptom of other problems, but if you're
> not seeing any other issues, then it's nothing to be concerned about.
>
Thx Gary,
this is my point: I see this many times in the (production) logs when
it is actually nothing to worry about. Should'nt this rather be a normal
response of a region server, instead an Exception?
Al
>
> On Wed, Mar 31, 2010 at 7:38 AM, Al Lias <al...@gmx.de> wrote:
>
>> As I do see this Exception really often in our logs. I wonder if this
>> indicates a regular thing (within splits etc) or if this is something
>> that should not normally happen.
>>
>> I see it often in Jira as a reason for something else that fails, but
>> for a regular client request, where the client not perfectly up-to-date
>> with region information it looks as something normal. Am I right here?
>>
>>
>> Al
>>
>
Re: Is NotServingRegionException really an Exception?
Posted by Gary Helmling <gh...@gmail.com>.
NotServingRegionException is a normal part of operations when regions
transition (ie due to splits). It's how the region server signals back to
the client that it needs to re-lookup the region location in .META. (which
is normally cached in memory by the client, so can become stale).
I'm sure it can also show up as a symptom of other problems, but if you're
not seeing any other issues, then it's nothing to be concerned about.
On Wed, Mar 31, 2010 at 7:38 AM, Al Lias <al...@gmx.de> wrote:
> As I do see this Exception really often in our logs. I wonder if this
> indicates a regular thing (within splits etc) or if this is something
> that should not normally happen.
>
> I see it often in Jira as a reason for something else that fails, but
> for a regular client request, where the client not perfectly up-to-date
> with region information it looks as something normal. Am I right here?
>
>
> Al
>