Agreed, but we need that check because we expect bytes for the checksum
computation right underneath. The bit that's odd is that we make the same check
again below:
try {
long crcValue = ia.readLong("crcvalue");
byte[] bytes = Util.readTxnBytes(ia);
// Since we preallocate, we define EOF to be an
if (bytes == null || bytes.length==0) {
throw new EOFException("Failed to read " + logFile);
}
// EOF or corrupted record
// validate CRC
Checksum crc = makeChecksumAlgorithm();
crc.update(bytes, 0, bytes.length);
if (crcValue != crc.getValue())
throw new IOException(CRC_ERROR);
if (bytes == null || bytes.length == 0)
return false;
hdr = new TxnHeader();
record = SerializeUtils.deserializeTxn(bytes, hdr);
} catch (EOFException e) {
I'm moving this discussion, to the jira, btw.
-Flavio
On 07 Jul 2014, at 22:03, Aaron Zimmerman <[email protected]> wrote:
> Flavio,
>
> Yes that is the initial error, and then the nodes in the cluster are
> restarted but fail to restart with
>
> 2014-07-04 12:58:52,734 [myid:1] - INFO [main:FileSnap@83] - Reading
> snapshot /var/lib/zookeeper/version-2/snapshot.300011fc0
> 2014-07-04 12:58:52,896 [myid:1] - DEBUG
> [main:FileTxnLog$FileTxnIterator@575] - Created new input stream
> /var/lib/zookeeper/version-2/log.300000021
> 2014-07-04 12:58:52,915 [myid:1] - DEBUG
> [main:FileTxnLog$FileTxnIterator@578] - Created new input archive
> /var/lib/zookeeper/version-2/log.300000021
> 2014-07-04 12:59:25,870 [myid:1] - DEBUG
> [main:FileTxnLog$FileTxnIterator@618] - EOF excepton java.io.EOFException:
> Failed to read /var/lib/zookeeper/version-2/log.300000021
> 2014-07-04 12:59:25,871 [myid:1] - DEBUG
> [main:FileTxnLog$FileTxnIterator@575] - Created new input stream
> /var/lib/zookeeper/version-2/log.300011fc2
> 2014-07-04 12:59:25,872 [myid:1] - DEBUG
> [main:FileTxnLog$FileTxnIterator@578] - Created new input archive
> /var/lib/zookeeper/version-2/log.300011fc2
> 2014-07-04 12:59:48,722 [myid:1] - DEBUG
> [main:FileTxnLog$FileTxnIterator@618] - EOF excepton java.io.EOFException:
> Failed to read /var/lib/zookeeper/version-2/log.300011fc2
>
> Thanks,
>
> AZ
>
>
> On Mon, Jul 7, 2014 at 3:33 PM, Flavio Junqueira <
> [email protected]> wrote:
>
>> I'm a bit confused, the stack trace you reported was this one:
>>
>> [QuorumPeer[myid=1]/0:0:0:0:0:0:0:0:2181:Follower@89] - Exception when
>> following the leader
>> java.io.EOFException
>> at java.io.DataInputStream.readInt(DataInputStream.java:375)
>> at
>> org.apache.jute.BinaryInputArchive.readInt(BinaryInputArchive.java:63)
>> at
>> org.apache.zookeeper.server.quorum.QuorumPacket.deserialize(QuorumPacket.java:83)
>> at
>> org.apache.jute.BinaryInputArchive.readRecord(BinaryInputArchive.java:108)
>> at
>> org.apache.zookeeper.server.quorum.Learner.readPacket(Learner.java:152)
>> at
>> org.apache.zookeeper.server.quorum.Follower.followLeader(Follower.java:85)
>> at
>> org.apache.zookeeper.server.quorum.QuorumPeer.run(QuorumPeer.java:740)
>>
>>
>> That's in a different part of the code.
>>
>> -Flavio
>>
>> On 07 Jul 2014, at 18:50, Aaron Zimmerman <[email protected]>
>> wrote:
>>
>>> Util.readTxnBytes reads from the buffer and if the length is 0, it return
>>> the zero length array, seemingly indicating the end of the file.
>>>
>>> Then this is detected in FileTxnLog.java:671:
>>>
>>> byte[] bytes = Util.readTxnBytes(ia);
>>> // Since we preallocate, we define EOF to be an
>>> if (bytes == null || bytes.length==0) {
>>> throw new EOFException("Failed to read " + logFile);
>>> }
>>>
>>>
>>> This exception is caught a few lines later, and the streams closed etc.
>>>
>>> So this seems to be not really an error condition, but a signal that the
>>> entire file has been read? Is this exception a red herring?
>>>
>>>
>>>
>>>
>>> On Mon, Jul 7, 2014 at 11:50 AM, Raúl Gutiérrez Segalés <
>> [email protected]
>>>> wrote:
>>>
>>>> On 7 July 2014 09:39, Aaron Zimmerman <[email protected]>
>> wrote:
>>>>
>>>>> What I don't understand is how the entire cluster could die in such a
>>>>> situation. I was able to load zookeeper locally using the snapshot and
>>>> 10g
>>>>> log file without apparent issue.
>>>>
>>>>
>>>> Sure, but it's syncing up with other learners that becomes challenging
>> when
>>>> having either big snapshots or too many txnlogs, right?
>>>>
>>>>
>>>>> I can see how large amounts of data could
>>>>> cause latency issues in syncing causing a single worker to die, but how
>>>>> would that explain the node's inability to restart? When the server
>>>>> replays the log file, does it have to sync the transactions to other
>>>> nodes
>>>>> while it does so?
>>>>>
>>>>
>>>> Given that your txn churn is so big, by the time it finished up reading
>>>> from disc it'll need
>>>> to catch up with the quorum.. how many txns have happened by that
>> point? By
>>>> the way, we use
>>>> this patch:
>>>>
>>>> https://issues.apache.org/jira/browse/ZOOKEEPER-1804
>>>>
>>>> to measure transaction rate, do you have any approximation of what your
>>>> transaction rate might be?
>>>>
>>>>
>>>>>
>>>>> I can alter the settings as has been discussed, but I worry that I'm
>> just
>>>>> delaying the same thing from happening again, if I deploy another storm
>>>>> topology or something. How can I get the cluster in a state where I
>> can
>>>> be
>>>>> confident that it won't crash in a similar way as load increases, or at
>>>>> least set up some kind of monitoring that will let me know something is
>>>>> unhealthy?
>>>>>
>>>>
>>>> I think it depends on what your txn rate is, lets measure that first I
>>>> guess.
>>>>
>>>>
>>>> -rgs
>>>>
>>
>>
