Looking further up in the logs (about 20 minutes prior in the logs when errors
first started happening), I noticed the following.
btw, ulimit -a shows that I have "open files" set to 64k. Is that not
sufficient?
2010-01-25 11:10:21,774 WARN org.apache.hadoop.hdfs.server.datanode.DataNode:
DatanodeRegistration(10.129.68.212:50010,
storageID=DS-1418567969-10.129.68.212-50010-1263610251776, infoPort=50075,
ipcPort=50020):Data\
XceiveServer: java.io.IOException: Too many open files
at sun.nio.ch.ServerSocketChannelImpl.accept0(Native Method)
at
sun.nio.ch.ServerSocketChannelImpl.accept(ServerSocketChannelImpl.java:145)
at sun.nio.ch.ServerSocketAdaptor.accept(ServerSocketAdaptor.java:84)
at
org.apache.hadoop.hdfs.server.datanode.DataXceiverServer.run(DataXceiverServer.java:130)
at java.lang.Thread.run(Thread.java:619)
2010-01-25 11:10:21,566 WARN org.apache.hadoop.hdfs.server.datanode.DataNode:
DatanodeRegistration(10.129.68.212:50010,
storageID=DS-1418567969-10.129.68.212-50010-1263610251776, infoPort=50075,
ipcPort=50020):Got \
exception while serving blk_3332344970774019423_10249 to /10.129.68.212:
java.io.FileNotFoundException:
/mnt/d1/HDFS-kannan1/current/subdir23/blk_3332344970774019423_10249.meta (Too
many open files)
at java.io.FileInputStream.open(Native Method)
at java.io.FileInputStream.<init>(FileInputStream.java:106)
at
org.apache.hadoop.hdfs.server.datanode.FSDataset.getMetaDataInputStream(FSDataset.java:682)
at
org.apache.hadoop.hdfs.server.datanode.BlockSender.<init>(BlockSender.java:97)
at
org.apache.hadoop.hdfs.server.datanode.DataXceiver.readBlock(DataXceiver.java:172)
at
org.apache.hadoop.hdfs.server.datanode.DataXceiver.run(DataXceiver.java:95)
at java.lang.Thread.run(Thread.java:619)
________________________________________
From: Kannan Muthukkaruppan [kan...@facebook.com]
Sent: Tuesday, January 26, 2010 7:01 AM
To: hbase-dev@hadoop.apache.org
Subject: RE: scanner lease expired/region server shutdown
1. Yes, it is a 5 node, setup.
1 Name Node/4 Data Nodes. Of the 4 DN, one is running the HBase Master, and the
other three are running region servers. ZK is on all the same 5 nodes. Should
ideally have separated this out. The nodes are 16GB, 4 disk machines.
2. I examined the HDFS datanode log on the same machine around that time the
problems happened, and saw this:
2010-01-25 11:33:09,531 WARN org.apache.hadoop.hdfs.server.datanode.DataNode:
DatanodeRegistration(10.129.68.212:50010,
storageID=DS-1418567969-10.129.68.212-50010-1263610251776, infoPort=50075,
ipcPort=\
50020):Got exception while serving blk_5691809099673541164_10475 to
/10.129.68.212:
java.net.SocketTimeoutException: 480000 millis timeout while waiting for
channel to be ready for write. ch : java.nio.channels.SocketChannel[connected
local=/10.129.68.212:50010 remote=/10.129.68.212:477\
29]
at
org.apache.hadoop.net.SocketIOWithTimeout.waitForIO(SocketIOWithTimeout.java:246)
at
org.apache.hadoop.net.SocketOutputStream.waitForWritable(SocketOutputStream.java:159)
at
org.apache.hadoop.net.SocketOutputStream.transferToFully(SocketOutputStream.java:198)
at
org.apache.hadoop.hdfs.server.datanode.BlockSender.sendChunks(BlockSender.java:313)
at
org.apache.hadoop.hdfs.server.datanode.BlockSender.sendBlock(BlockSender.java:400)
at
org.apache.hadoop.hdfs.server.datanode.DataXceiver.readBlock(DataXceiver.java:180)
at
org.apache.hadoop.hdfs.server.datanode.DataXceiver.run(DataXceiver.java:95)
at java.lang.Thread.run(Thread.java:619)
[For future runs, will try to turn on Java GC logging as well as per your
suggestion.]
3. You wrote <<< There is no line after the above? A region with a startkey
of 0031841132? >>>
I just cut-paste a section of the PE log and the scan of the '.META.' from
shell. But there were many such regions for which the PE client reported errors
of the form:
10/01/25 12:31:37 DEBUG client.HConnectionManager$TableServers:
locateRegionInMeta attempt 1 of 10 failed; retrying after sleep of 1000
because: Connection refused
10/01/25 12:31:37 DEBUG client.HConnectionManager$TableServers: Removed
.META.,,1 for tableName=.META. from cache because of
TestTable,0015411453,99999999999999
10/01/25 12:31:37 DEBUG client.HConnectionManager$TableServers: Cached location
for .META.,,1 is 10.129.68.212:60020
and scan of '.META.' revealed that those regions, such as the
'TestTable,0015411453,99999999999999', had splitA & splitB portions in META.
<<< Then its a dropped edit of .META. The parent region -- the one being split
got updates which added the splitA and splitB and its offlining but the new
region didn't get inserted? The crash happened just at that time?>>>
Didn't fully understand the above.
<<< It would be interesting to take a look at the regionserver logs from that
time. Please post if you have a moment so we can take a looksee.>>>
Will do. Should I just send it as an attachment to the list? Or is their a
recommended way of doing this?
regards,
Kannan
________________________________________
From: saint....@gmail.com [saint....@gmail.com] On Behalf Of Stack
[st...@duboce.net]
Sent: Monday, January 25, 2010 8:59 PM
To: hbase-dev@hadoop.apache.org
Subject: Re: scanner lease expired/region server shutdown
What J-D said but with ornamentation. See below.
On Mon, Jan 25, 2010 at 7:14 PM, Kannan Muthukkaruppan
<kan...@facebook.com> wrote:
> I was doing some brute force testing - running one instance of
> PerformanceEvaluation (PE) for writes, and another instance for randomReads.
>
Whats the cluster your hitting like? That 5-node thingy? Whats the
hardware profile.
> One of the region servers went down after a while. [This is on 0.20.2]. The
> region server log had things like:
>
> 2010-01-25 11:33:39,416 WARN org.apache.hadoop.hbase.regionserver.HLog: IPC
> Server handler 34 on 60020 took 65190ms appending an edit to hlog;
> editcount=27878
This is saying that it took 65 seconds to append to hdfs. What was
going on at that time? A fat GC in the regionserver or over in a
Datanode? You can enable GC logging uncommenting stuff in the
hbase-env.sh. Feed the GC log to https://gchisto.dev.java.net/
(suggested by the zookeeper lads). Its good for finding the long
pauses. We should find the logs around the long GC pause. Its
probably a failed promotion that brought on the stop-the-world GC. Or
your HDFS was struggling?
I was going to say that the PE puts the worse kind of loading on the
hbase cache -- nothing sticks around -- but looking at your numbers
below, cache seems to be working pretty well.
> 2010-01-25 11:33:39,416 DEBUG org.apache.hadoop.hbase.io.hfile.LruBlockCache:
> Cache Stats: Sizes: Total=1815.4441MB (1903631104), Free=581.23096MB
> (609464832),\
> Max=2396.675MB (2513095936), Counts: Blocks=28216, Access=10904689,
> Hit=9313612, Miss=1591077, Evictions=110, Evicted=414336, Ratios: Hit
> Ratio=85.40924191474\
> 915%, Miss Ratio=14.590759575366974%, Evicted/Run=3766.69091796875
> 2010-01-25 11:33:39,417 WARN org.apache.hadoop.hbase.regionserver.HLog: IPC
> Server handler 52 on 60020 took 65195ms appending an edit to hlog;
> editcount=27879
> 2010-01-25 11:33:39,417 WARN org.apache.hadoop.hbase.regionserver.HLog: IPC
> Server handler 75 on 60020 took 65195ms appending an edit to hlog;
> editcount=27880
> 2010-01-25 11:33:39,417 INFO
> org.apache.hadoop.hbase.regionserver.HRegionServer: Scanner
> -5220035164735014996 lease expired
>
> This was followed by:
> 2010-01-25 11:33:39,636 WARN org.apache.zookeeper.ClientCnxn: Exception
> closing session 0x12652c620520001 to
> sun.nio.ch.selectionkeyi...@788ab708<mailto:sun.nio.ch.selectionkeyi...@788ab708>
> java.io.IOException: TIMED OUT
This is the zk timeout.
>
> And also errors like:
> 2010-01-25 11:33:39,692 ERROR
> org.apache.hadoop.hbase.regionserver.HRegionServer:
> org.apache.hadoop.hbase.UnknownScannerException: Name: -5220035164735014996
>
These will happen after the above. The regionserver is on its way
down. Probably emptied the list of outstanding regions.
> Subsequently, I restarted the region server and just started the PE in
> sequentialWrite mode. It seems to be off to a really slow start. For several
> regions, it is printing the following:
>
> 10/01/25 18:12:44 DEBUG client.HConnectionManager$TableServers:
> locateRegionInMeta attempt 0 of 10 failed; retrying after sleep of 1000
> because: region offline: TestTable,0031841132,1264121653303
> 10/01/25 18:12:44 DEBUG client.HConnectionManager$TableServers: Removed
> .META.,,1 for tableName=.META. from cache because of
> TestTable,0032000000,99999999999999
> 10/01/25 18:12:44 DEBUG client.HConnectionManager$TableServers: Cached
> location for .META.,,1 is 10.129.68.212:60020
> 10/01/25 18:12:45 DEBUG client.HConnectionManager$TableServers:
> locateRegionInMeta attempt 1 of 10 failed; retrying after sleep of 1000
> because: region offline: TestTable,0031841132,1264121653303
> 10/01/25 18:12:45 DEBUG client.HConnectionManager$TableServers: Removed
> .META.,,1 for tableName=.META. from cache because of
> TestTable,0032000000,99999999999999
> [..and so on..]
> 10/01/25 18:12:59 DEBUG client.HConnectionManager$TableServers: Cached
> location for .META.,,1 is 10.129.68.212:60020
> 10/01/25 18:13:07 DEBUG client.HConnectionManager$TableServers:
> locateRegionInMeta attempt 8 of 10 failed; retrying after sleep of 16000
> because: region offline: TestTable,0031841132,1264121653303
> 10/01/25 18:13:07 DEBUG client.HConnectionManager$TableServers: Removed
> .META.,,1 for tableName=.META. from cache because of
> TestTable,0032000000,99999999999999
>
> When I scan the '.META.', I noticed that most of the regions for which I get
> the above error were in the middle of (?) a split. For example:
>
> TestTable,0031841132,126412 column=info:regioninfo, timestamp=1264470099796,
> value=REGION => {NAME => 'TestTa
> 1653303 ble,0031841132,1264121653303', STARTKEY =>
> '0031841132', ENDKEY => '0032057774',
> ENCODED => 644500792, OFFLINE => true, SPLIT =>
> true, TABLE => {{NAME => 'TestTab
> le', FAMILIES => [{NAME => 'info', VERSIONS =>
> '3', COMPRESSION => 'NONE', TTL =>
> '2147483647', BLOCKSIZE => '65536', IN_MEMORY =>
> 'false', BLOCKCACHE => 'true'}]
> }}
> TestTable,0031841132,126412 column=info:server, timestamp=1264121655148,
> value=10.129.68.214:60020
> 1653303
> TestTable,0031841132,126412 column=info:serverstartcode,
> timestamp=1264121655148, value=1264109117245
> 1653303
> TestTable,0031841132,126412 column=info:splitA, timestamp=1264470099796,
> value=\000\n0031978284\000\000\000\0
> 1653303
> 01&g\016\357\277\275\024\"TestTable,0031841132,1264449401108\000\n0031841132\000\
>
> 000\000\005\tTestTable\000\000\000\000\000\002\000\000\000\aIS_ROOT\000\000\000\0
>
> 05false\000\000\000\aIS_META\000\000\000\005false\000\000\000\001\a\004info\000\0
>
> 00\000\a\000\000\000\vBLOOMFILTER\000\000\000\005false\000\000\000\vCOMPRESSION\0
>
> 00\000\000\004NONE\000\000\000\bVERSIONS\000\000\000\0013\000\000\000\003TTL\000\
>
> 000\000\n2147483647\000\000\000\tBLOCKSIZE\000\000\000\00565536\000\000\000\tIN_M
>
> EMORY\000\000\000\005false\000\000\000\nBLOCKCACHE\000\000\000\004true\357\277\27
> 5\337\274#
> TestTable,0031841132,126412 column=info:splitB, timestamp=1264470099796,
> value=\000\n0032057774\000\000\000\0
> 1653303
> 01&g\016\357\277\275\024\"TestTable,0031978284,1264449401108\000\n0031978284\000\
>
> 000\000\005\tTestTable\000\000\000\000\000\002\000\000\000\aIS_ROOT\000\000\000\0
>
> 05false\000\000\000\aIS_META\000\000\000\005false\000\000\000\001\a\004info\000\0
>
> 00\000\a\000\000\000\vBLOOMFILTER\000\000\000\005false\000\000\000\vCOMPRESSION\0
>
> 00\000\000\004NONE\000\000\000\bVERSIONS\000\000\000\0013\000\000\000\003TTL\000\
>
> 000\000\n2147483647\000\000\000\tBLOCKSIZE\000\000\000\00565536\000\000\000\tIN_M
>
> EMORY\000\000\000\005false\000\000\000\nBLOCKCACHE\000\000\000\004truej\357\277\2
> 75\312\262
>
> Any thoughts/ideas on what might be going on? Appreciate any input in helping
> understand what might be going on.
>
There is no line after the above? A region with a startkey of
0031841132? Then its a dropped edit of .META. The parent region --
the one being split got updates which added the splitA and splitB and
its offlining but the new region didn't get inserted? The crash
happened just at that time?
It would be interesting to take a look at the regionserver logs from
that time. Please post if you have a moment so we can take a looksee.
Above kinda thing is what the master rewrite is about moving state
transitions up to zk so atomic over cluster moving regions through
transitions rather than as here, a multi-row update might not all go
through as things currently work.
St.Ack
> Regards,
> Kannan
>
>
>
