Return-Path: X-Original-To: apmail-cassandra-user-archive@www.apache.org Delivered-To: apmail-cassandra-user-archive@www.apache.org Received: from mail.apache.org (hermes.apache.org [140.211.11.3]) by minotaur.apache.org (Postfix) with SMTP id 5074E104C2 for ; Mon, 22 Jul 2013 08:33:54 +0000 (UTC) Received: (qmail 7422 invoked by uid 500); 22 Jul 2013 08:33:51 -0000 Delivered-To: apmail-cassandra-user-archive@cassandra.apache.org Received: (qmail 7402 invoked by uid 500); 22 Jul 2013 08:33:51 -0000 Mailing-List: contact user-help@cassandra.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: user@cassandra.apache.org Delivered-To: mailing list user@cassandra.apache.org Received: (qmail 7394 invoked by uid 99); 22 Jul 2013 08:33:50 -0000 Received: from athena.apache.org (HELO athena.apache.org) (140.211.11.136) by apache.org (qpsmtpd/0.29) with ESMTP; Mon, 22 Jul 2013 08:33:50 +0000 X-ASF-Spam-Status: No, hits=1.5 required=5.0 tests=HTML_MESSAGE,RCVD_IN_DNSWL_LOW,SPF_PASS X-Spam-Check-By: apache.org Received-SPF: pass (athena.apache.org: domain of sylvain@datastax.com designates 209.85.220.52 as permitted sender) Received: from [209.85.220.52] (HELO mail-pa0-f52.google.com) (209.85.220.52) by apache.org (qpsmtpd/0.29) with ESMTP; Mon, 22 Jul 2013 08:33:46 +0000 Received: by mail-pa0-f52.google.com with SMTP id kq13so1250936pab.39 for ; Mon, 22 Jul 2013 01:33:25 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type:x-gm-message-state; bh=Maiu/qAwDKpjPHi+r4xuzxyaSCNlueFCUdcjbu4JljM=; b=lq5U/Ol5VilLa9quwcgelEsNlP3nJsUatDYnfi5Y+OcFdHniuOiAkXzPpKHBcMAiro H+KmRF6C1ebXS9rUhdM57x2q+tTh/F4gdvC71LfRu27Tc7AbLY/nQjiagSdKRhJGPEFq S615rEKlfTGCKeJZial4zPq0ANMAfoClKZJ4TQ+dfCx4rcM0Eh+7MdHq+eyJhuowj1gY b0wo+CQR9hOnG5KpeUyzul1BsiHwW0ibqPIv1cUyvk9sadAuCuMlA0NqotAqgpJIA/ie tjzjC0FeYYaVqJTfKlZq9roiEQ6SZZoLSU6mgv+IIgbkilknUS1Emn24BwkIQ0/kB62X TIow== MIME-Version: 1.0 X-Received: by 10.66.135.146 with SMTP id ps18mr30019786pab.172.1374482005778; Mon, 22 Jul 2013 01:33:25 -0700 (PDT) Received: by 10.68.88.37 with HTTP; Mon, 22 Jul 2013 01:33:25 -0700 (PDT) In-Reply-To: References: Date: Mon, 22 Jul 2013 10:33:25 +0200 Message-ID: Subject: Re: Cassandra 2.0 - AssertionError in ArrayBackedSortedColumns From: Sylvain Lebresne To: "user@cassandra.apache.org" Content-Type: multipart/alternative; boundary=485b395e7f2db476c704e215875e X-Gm-Message-State: ALoCoQnJA1RHidvx++r87XbRc4bAZ+BgrrKRs+U9Uhoi5iKmXcpKLiEEWMJ5D1dBCrtUEu5QWqr1 X-Virus-Checked: Checked by ClamAV on apache.org --485b395e7f2db476c704e215875e Content-Type: text/plain; charset=ISO-8859-1 Actually, your second stack trace is due to https://issues.apache.org/jira/browse/CASSANDRA-5788. On Mon, Jul 22, 2013 at 9:37 AM, Sylvain Lebresne wrote: > > unless data was stored in incorrect order and I don't know if that is >> possible through the API.. >> > > That's exactly what happens and that's why I say it's a bug. > > >> >> ii. I am also seeing some sporadic cases where a single column cas() >> update is hitting this same issue (the bug you mentioned) as multiple >> columns, do you see any reason for that happening? >> > > That would be slightly weirder, but frankly that's almost surely due to > https://issues.apache.org/jira/browse/CASSANDRA-5786 too. > > -- > Sylvain > > >> Thank you, >> Soumava >> >> >> On Mon, Jul 22, 2013 at 12:11 AM, Sylvain Lebresne wrote: >> >>> This is a bug really: >>> https://issues.apache.org/jira/browse/CASSANDRA-5786. >>> >>> This should get fixed in the next beta of 2.0, but if you really want to >>> test CAS updates in the meantime, you'll have to provide the columns in >>> (column family comparator) sorted order to the thrift cas() method. >>> >>> -- >>> Sylvain >>> >>> >>> On Sun, Jul 21, 2013 at 1:22 PM, Soumava Ghosh wrote: >>> >>>> Hi, >>>> >>>> I'm taking a look at the Check and Set functionalities provided by the >>>> cas() API provided by cassandra 2.0 (the code available on git). I'm >>>> running a few tests on a small sized cluster (replication factor 3, >>>> consistency level quorum) with a few clients. I've observed a lot of cases >>>> seem to hit the TimedOutException while paxos is in progress. On inspection >>>> of the server side logs the following stack was seen: >>>> >>>> ERROR [Thread-582] 2013-07-21 01:17:46,169 CassandraDaemon.java (line >>>> 196) Exception in thread Thread[Thread-582,5,main] >>>> java.lang.AssertionError: Added column does not sort as the last column >>>> at >>>> org.apache.cassandra.db.ArrayBackedSortedColumns.addColumn(ArrayBackedSortedColumns.java:115) >>>> at >>>> org.apache.cassandra.db.ColumnFamily.addColumn(ColumnFamily.java:117) >>>> at >>>> org.apache.cassandra.db.ColumnFamilySerializer.deserialize(ColumnFamilySerializer.java:119) >>>> at >>>> org.apache.cassandra.db.ColumnFamilySerializer.deserialize(ColumnFamilySerializer.java:96) >>>> at >>>> org.apache.cassandra.db.ColumnFamilySerializer.deserialize(ColumnFamilySerializer.java:91) >>>> at >>>> org.apache.cassandra.service.paxos.Commit$CommitSerializer.deserialize(Commit.java:139) >>>> at >>>> org.apache.cassandra.service.paxos.Commit$CommitSerializer.deserialize(Commit.java:128) >>>> at org.apache.cassandra.net.MessageIn.read(MessageIn.java:99) >>>> at >>>> org.apache.cassandra.net.IncomingTcpConnection.receiveMessage(IncomingTcpConnection.java:175) >>>> at >>>> org.apache.cassandra.net.IncomingTcpConnection.handleModernVersion(IncomingTcpConnection.java:135) >>>> at >>>> org.apache.cassandra.net.IncomingTcpConnection.run(IncomingTcpConnection.java:82) >>>> >>>> I was updating multiple columns using the same cas() call, and looking >>>> at the assert (code below) I added code to sort them before sending. >>>> However, now I'm seeing the same issue *even with single column* cas() >>>> calls. >>>> >>>> int c = >>>> internalComparator().compare(columns.get(getColumnCount() - 1).name(), >>>> column.name()); >>>> // note that we want an assertion here (see addColumn javadoc), >>>> but we also want that if >>>> // assertion are disabled, addColumn works correctly with >>>> unsorted input >>>> assert c <= 0 : "Added column does not sort as the " + >>>> (reversed ? "first" : "last") + " column"; >>>> >>>> I have also seen this error occur in the getRow() path, as below: >>>> >>>> java.lang.AssertionError: Added column does not sort as the last column >>>> at >>>> org.apache.cassandra.db.ArrayBackedSortedColumns.addColumn(ArrayBackedSortedColumns.java:115) >>>> at >>>> org.apache.cassandra.db.ColumnFamily.addColumn(ColumnFamily.java:117) >>>> at >>>> org.apache.cassandra.db.ColumnFamily.addAtom(ColumnFamily.java:151) >>>> at >>>> org.apache.cassandra.db.CollationController.collectTimeOrderedData(CollationController.java:95) >>>> at >>>> org.apache.cassandra.db.CollationController.getTopLevelColumns(CollationController.java:57) >>>> at >>>> org.apache.cassandra.db.ColumnFamilyStore.getTopLevelColumns(ColumnFamilyStore.java:1452) >>>> at >>>> org.apache.cassandra.db.ColumnFamilyStore.getColumnFamily(ColumnFamilyStore.java:1281) >>>> at >>>> org.apache.cassandra.db.ColumnFamilyStore.getColumnFamily(ColumnFamilyStore.java:1195) >>>> at org.apache.cassandra.db.Table.getRow(Table.java:331) >>>> at >>>> org.apache.cassandra.db.SliceByNamesReadCommand.getRow(SliceByNamesReadCommand.java:55) >>>> at >>>> org.apache.cassandra.service.StorageProxy$LocalReadRunnable.runMayThrow(StorageProxy.java:1288) >>>> at >>>> org.apache.cassandra.service.StorageProxy$DroppableRunnable.run(StorageProxy.java:1813) >>>> at >>>> java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) >>>> at >>>> java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) >>>> at java.lang.Thread.run(Thread.java:722) >>>> >>>> Could someone provide me a little more clarity about what the context >>>> of the error is and what the client needs to do to fix it? I understand >>>> that running with assertions disabled would do away with this error, but >>>> i'd like to know if there is a proper way to fix this. Moreover, what could >>>> possibly be going wrong in the get path that is hitting this issue? >>>> >>>> Some guidance, on the fact that whether it is expected that the client >>>> sort the columns before calling the API with multiple columns, would be >>>> really appreciated. >>>> >>>> Thanks, >>>> Soumava >>>> >>> >>> >> > --485b395e7f2db476c704e215875e Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable
Actually, your second stack trace is due to=A0https://issues.apache.= org/jira/browse/CASSANDRA-5788.

On Mon, Jul 22, 2013 at 9:37 AM, Sylvain Lebresne <sylvain@datastax.com= > wrote:

=
=A0unless data was stored in incorrect order and I do= n't know if that is possible through the API..
=

That's exactly what happens and that's wh= y I say it's a bug.
=A0

ii. I am also seeing some sporadic cases where a single= column cas() update is hitting this same issue (the bug you mentioned) as = multiple columns, do you see any reason for that happening?

That would be slightly weirder, but = frankly that's almost surely due to https://issues.apache.org/j= ira/browse/CASSANDRA-5786 too.

--
Sylvain
<= br>

Thank you,
Soumava


On Mon, Jul 22, 20= 13 at 12:11 AM, Sylvain Lebresne <sylvain@datastax.com> w= rote:
This is a bug really:=A0https://i= ssues.apache.org/jira/browse/CASSANDRA-5786.

This should get fixed in the next beta of 2.0, but if you re= ally want to test CAS updates in the meantime, you'll have to provide t= he columns in (column family comparator) sorted order to the thrift cas() m= ethod.

--
Sylvain


On Sun, Jul 21, 2013 at 1:= 22 PM, Soumava Ghosh <soumava@cs.utexas.edu> wrote:
Hi,

I'm taking a l= ook at the Check and Set functionalities provided by the cas() API provided= by cassandra 2.0 (the code available on git). I'm running a few tests = on a small sized cluster (replication factor 3, consistency level quorum) w= ith a few clients. I've observed a lot of cases seem to hit the TimedOu= tException while paxos is in progress. On inspection of the server side log= s the following stack was seen:

ERROR [Thread-582] 2013-07-21 01:17:46,169 Cassand= raDaemon.java (line 196) Exception in thread Thread[Thread-582,5,main]
java.lang.AssertionError: Added column does not sort as the last colu= mn
=A0 =A0 =A0 =A0 at org.apache.cassandra.db.ArrayBackedSortedColumns.ad= dColumn(ArrayBackedSortedColumns.java:115)
=A0 =A0 =A0 =A0 at org= .apache.cassandra.db.ColumnFamily.addColumn(ColumnFamily.java:117)
=A0 =A0 =A0 =A0 at org.apache.cassandra.db.ColumnFamilySerializer.deseria= lize(ColumnFamilySerializer.java:119)
=A0 =A0 =A0 =A0 at org.apache.cassandra.db.ColumnFamilySerializer.dese= rialize(ColumnFamilySerializer.java:96)
=A0 =A0 =A0 =A0 at org.ap= ache.cassandra.db.ColumnFamilySerializer.deserialize(ColumnFamilySerializer= .java:91)
=A0 =A0 =A0 =A0 at org.apache.cassandra.service.paxos.Commit$CommitSer= ializer.deserialize(Commit.java:139)
=A0 =A0 =A0 =A0 at org.apach= e.cassandra.service.paxos.Commit$CommitSerializer.deserialize(Commit.java:1= 28)
=A0 =A0 =A0 =A0 at org.apache.cassandra.net.MessageIn.read(MessageIn.java:9= 9)
=A0 =A0 =A0 =A0 at org.apache.cassandra.net.IncomingTcpConnect= ion.receiveMessage(IncomingTcpConnection.java:175)
=A0 =A0 =A0 = =A0 at org.apache.cassandra.net.IncomingTcpConnection.handleModernVersion(I= ncomingTcpConnection.java:135)
=A0 =A0 =A0 =A0 at org.apache.cassandra.net.IncomingTcpConnection.run(= IncomingTcpConnection.java:82)

I was updating mult= iple columns using the same cas() call, and looking at the assert (code bel= ow) I added code to sort them before sending.=A0
However, now I'm seeing the same issue even=A0with=A0single col= umn cas() calls.=A0

=A0 =A0 =A0 =A0 int c =3D internalComparator().compare(col= umns.get(getColumnCount() - 1).name(), column.name());
=A0 =A0 =A0 = =A0 // note that we want an assertion here (see addColumn javadoc), but we = also want that if
=A0 =A0 =A0 =A0 // assertion are disabled, addColumn works = correctly with unsorted input
=A0 =A0 =A0 =A0 assert c <=3D= 0 : "Added column does not sort as the " + (reversed ? "fir= st" : "last") + " column";

I have also s= een this error occur in the getRow() path, as below:

java.lang.AssertionError: Added column does not so= rt as the last column
=A0 =A0 =A0 = =A0 at org.apache.cassandra.db.ArrayBackedSortedColumns.addColumn(ArrayBack= edSortedColumns.java:115)
=A0 =A0 = =A0 =A0 at org.apache.cassandra.db.ColumnFamily.addColumn(ColumnFamily.java= :117)
=A0 =A0 =A0 = =A0 at org.apache.cassandra.db.ColumnFamily.addAtom(ColumnFamily.java:151)<= /span>
=A0 =A0 =A0 =A0 at org.apache.cass= andra.db.CollationController.collectTimeOrderedData(CollationController.jav= a:95)
=A0 =A0 =A0 = =A0 at org.apache.cassandra.db.CollationController.getTopLevelColumns(Colla= tionController.java:57)<= br>=A0 =A0 = =A0 =A0 at org.apache.cassandra.db.ColumnFamilyStore.getTopLevelColumns(Col= umnFamilyStore.java:1452)
=A0 =A0 =A0 = =A0 at org.apache.cassandra.db.ColumnFamilyStore.getColumnFamily(ColumnFami= lyStore.java:1281)
=A0 =A0 =A0 =A0= at org.apache.cassandra.db.ColumnFamilyStore.getColumnFamily(ColumnFamilyS= tore.java:1195)
=A0 =A0 =A0 = =A0 at org.apache.cassandra.db.Table.getRow(Table.java:331)
=A0 =A0 =A0 =A0 at org.apache.cassandra.db.SliceB= yNamesReadCommand.getRow(SliceByNamesReadCommand.java:55)
=A0 =A0 =A0 = =A0 at org.apache.cassandra.service.StorageProxy$LocalReadRunnable.runMayTh= row(StorageProxy.java:1288)
=A0 = =A0 =A0 =A0 at org.apache.cassandra.service.StorageProxy$DroppableRunnable.= run(StorageProxy.java:1813)
=A0 =A0 =A0 = =A0 at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor= .java:1145)
=A0 =A0 =A0 =A0 at jav= a.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615= )
=A0 =A0 =A0 = =A0 at java.lang.Thread.run(Thread.java:722)

Could someone prov= ide me a little more clarity about what the context of the error is and wha= t the client needs to do to fix it? I understand that running with assertio= ns disabled would do away with this error, but i'd like to know if ther= e is a proper way to fix this. Moreover, what could possibly be going wrong= in the get path that is hitting this issue?

Some guidance, on the fact that whether it is exp= ected that the client sort the columns before calling the API with multiple= columns, would be really appreciated.

Thanks,
Soumava




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