Return-Path: X-Original-To: apmail-hadoop-mapreduce-user-archive@minotaur.apache.org Delivered-To: apmail-hadoop-mapreduce-user-archive@minotaur.apache.org Received: from mail.apache.org (hermes.apache.org [140.211.11.3]) by minotaur.apache.org (Postfix) with SMTP id E3A53D2D2 for ; Mon, 19 Nov 2012 02:36:20 +0000 (UTC) Received: (qmail 15939 invoked by uid 500); 19 Nov 2012 02:36:16 -0000 Delivered-To: apmail-hadoop-mapreduce-user-archive@hadoop.apache.org Received: (qmail 15826 invoked by uid 500); 19 Nov 2012 02:36:15 -0000 Mailing-List: contact user-help@hadoop.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: user@hadoop.apache.org Delivered-To: mailing list user@hadoop.apache.org Received: (qmail 15787 invoked by uid 99); 19 Nov 2012 02:36:14 -0000 Received: from athena.apache.org (HELO athena.apache.org) (140.211.11.136) by apache.org (qpsmtpd/0.29) with ESMTP; Mon, 19 Nov 2012 02:36:14 +0000 X-ASF-Spam-Status: No, hits=2.2 required=5.0 tests=HTML_MESSAGE,RCVD_IN_DNSWL_NONE,SPF_PASS X-Spam-Check-By: apache.org Received-SPF: pass (athena.apache.org: local policy) Received: from [98.138.91.66] (HELO nm7-vm0.bullet.mail.ne1.yahoo.com) (98.138.91.66) by apache.org (qpsmtpd/0.29) with ESMTP; Mon, 19 Nov 2012 02:36:04 +0000 Received: from [98.138.226.178] by nm7.bullet.mail.ne1.yahoo.com with NNFMP; 19 Nov 2012 02:35:43 -0000 Received: from [98.138.226.166] by tm13.bullet.mail.ne1.yahoo.com with NNFMP; 19 Nov 2012 02:35:43 -0000 Received: from [127.0.0.1] by omp1067.mail.ne1.yahoo.com with NNFMP; 19 Nov 2012 02:35:43 -0000 X-Yahoo-Newman-Property: ymail-3 X-Yahoo-Newman-Id: 885401.50776.bm@omp1067.mail.ne1.yahoo.com Received: (qmail 34816 invoked by uid 60001); 19 Nov 2012 02:35:43 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yahoo.com; s=s1024; t=1353292543; bh=j0sn9siODtIyvaE42PvZEe2i9f4eHZ2F/hxLn8NINeo=; h=X-YMail-OSG:Received:X-Rocket-MIMEInfo:X-Mailer:Message-ID:Date:From:Reply-To:Subject:To:MIME-Version:Content-Type; b=SnaZ1XZS9dzPL5eXaAMUD9clPDhrJN562taZc8zJCPyoi2bDSstzCpbb3uoNpr6SvFqFV4wCLXSilYM+Ol/104HzlGP2qEF2k9gMeYEWB1PPQFSZ3/FjLvZ52OJFZHySC3Nm1e0pdA6zPFGZSG7joSEvNeNWn3iKKodG5Kod8+0= DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com; h=X-YMail-OSG:Received:X-Rocket-MIMEInfo:X-Mailer:Message-ID:Date:From:Reply-To:Subject:To:MIME-Version:Content-Type; b=dvDdfwav17wRldibXm6shSrLXbr7PspBlS5oJXZxVsw9/gT7RGVE0VrNluVK+l5kc3j9Hd++5o/c5ri6585InP3NAjy8xTHwcfyR0YUpLfSGCGPeFoQ9QsfWcHWjLNm8IgZzv9wyWxFesrOotQ+4UWRwKiDTDzmQtPG2yLNHpXo=; X-YMail-OSG: n1ppPggVM1l.tdo2CU6OwvIymdgoLAHmqqwn8tI139gRzfJ erOp6Sg0B4XBzb_tvRW9s4dsC6VFOO_S7pAK1vFn2tNeHOAEzdciI_Lixrc7 w1TkWoqeS7YRb2rmPERpCM_GGuSqYCpjtCW92UONuUh0MqP1_bqtNmIbPgOx w1R8qcH9GsGJfATQLwN0MX99fijKrzCUyjtjO8c66jxOjW0kas34X6Vane_O momZSBvKkGM7PtBfUUl38BNlKA3Os5BAC.r33kL3zIZT.u.so9ic5fuaFrSa yCyL0jNRqBTWEjYxhLEi71bSpJup5py9oqkEDN8vgUYQvjOzyK7D2mPFmSmM hAKXLFpsGIT9hqsMdZBk0h0sCCONC21FeHPn6.xgCsLm3L0EWcSgiXa8vx8s .sLKtXsvF.RnICvNj6g1RkliE145SitnZ5tPGUc0Pwg-- Received: from [24.21.16.40] by web125404.mail.ne1.yahoo.com via HTTP; Sun, 18 Nov 2012 18:35:43 PST X-Rocket-MIMEInfo: 001.001,SGksCgpJIGhhdmUgSGFkb29wIDEuMC4zIHJ1bm5pbmcgb24gVWJ1bnR1IExpbnV4LiBJIGFtIHBsYXlpbmcgYXJvdW5kIHdpdGggYSBzaW1wbGUgTWFwLVJlZHVjZSBqb2IuCgpEZXRhaWxzIG9mIHRoZSBjb2RlCj09PT09PT09PT09PT0KMS4gU2luY2UgdGhpcyBleGVyY2lzZSBpcyBtYWlubHkgdG8gbGVhcm4gYmFzaWMgSGFkb29wIEFQSXMgYW5kIGxlYXJuIGhvdyB0byBydW4gdGhlc2Ugam9icywgdGhlIGxvZ2ljIGluIHRoZSBNYXAgam9iIGlzIGlycmVsZXZhbnQuIAoyLiBUaGUgY29kZSBzbmlwcGV0IGkBMAEBAQE- X-Mailer: YahooMailWebService/0.8.123.460 Message-ID: <1353292543.91431.YahooMailNeo@web125404.mail.ne1.yahoo.com> Date: Sun, 18 Nov 2012 18:35:43 -0800 (PST) From: Utester Utester Reply-To: Utester Utester Subject: java.lang.ClassCastException: org.apache.hadoop.io.LongWritable cannot be cast to java.lang.String To: "user@hadoop.apache.org" MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="-560092261-2096705700-1353292543=:91431" X-Virus-Checked: Checked by ClamAV on apache.org ---560092261-2096705700-1353292543=:91431 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable Hi,=0A=0AI have Hadoop 1.0.3 running on Ubuntu Linux. I am playing around w= ith a simple Map-Reduce job.=0A=0ADetails of the code=0A=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=0A1. Since this exercise is mainly to learn basic Had= oop APIs and learn how to run these jobs, the logic in the Map job is irrel= evant. =0A2. The code snippet is below with just the APIs (which I believe = is causing a problem - PLEASE correct me if I am wrong and I will post the = entire code snippet)public=0A=A0=0A....=0A....public=0A=A0 Reporter reporte= r) =0A...=0A...=0A}publicvoidmap(String sourceKey, String sourceValue, Outp= utCollector outputC,throwsIOException {=0A=A0=0A}=0A=A0=0AE= xception:=0A=0Ahduser@utester-VirtualBox:/usr/local/hadoop/bin$ /usr/local/= hadoop/bin/hadoop jar ~/HadoopCodeProjectsFolder/JobOrganizerMapRedProject/= 11182012/HadoopMapRedProject.jar org.u.hadoopmapred.JobOrganizer=0AWarning:= $HADOOP_HOME is deprecated.=0A12/11/18 16:36:22 WARN mapred.JobClient: Use= GenericOptionsParser for parsing the arguments. Applications should implem= ent Tool for the same.=0A12/11/18 16:36:22 INFO util.NativeCodeLoader: Load= ed the native-hadoop library=0A12/11/18 16:36:22 WARN snappy.LoadSnappy: Sn= appy native library not loaded=0A12/11/18 16:36:22 INFO mapred.FileInputFor= mat: Total input paths to process : 1=0A12/11/18 16:36:22 INFO mapred.JobCl= ient: Running job: job_201211181608_0002=0A12/11/18 16:36:23 INFO mapred.Jo= bClient:=A0 map 0% reduce 0%=0A12/11/18 16:36:42 INFO mapred.JobClient: Tas= k Id : attempt_201211181608_0002_m_000000_0, Status : FAILED=0Ajava.lang.Cl= assCastException: org.apache.hadoop.io.LongWritable cannot be cast to java.= lang.String=0A=A0at org.u.hadoopmapred.JobOrganizer$JobOrganizerMapper.map(= JobOrganizer.java:1)=0A=A0at org.apache.hadoop.mapred.MapRunner.run(MapRunn= er.java:50)=0A=A0at org.apache.hadoop.mapred.MapTask.runOldMapper(MapTask.j= ava:436)=0A=0A=0A=A0=0AThe Mapper Interface as per the javadoc is: Interfac= e Mapper and its map function is: map(K1 key, V1 value, Ou= tputCollector output, Reporter). I wanted to=A0parameterize K1, V1,= K2, V2 to all be String. Is something wrong in the way I am thinking? Is t= his what is wrong? I have found similar questions on the internet but the a= snwers did not clarify how I am breaking the Mapper contract (I did not hav= e any compile errors - just a runtime error). =0A=A0=0A=A0=0A=A0=0AThanks= =A0=0A@OverridestaticclassJobOrganizerMapper extendsMapReduceBase implement= sMapper {classJobOrganizer ---560092261-2096705700-1353292543=:91431 Content-Type: text/html; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable
Hi,
 
I have Hadoop 1.0.3 running on Ubuntu Linux. I am playing around with = a simple Map-Reduce job.
 
Details of the code
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
1. Since this exercise is mainly to learn basic Hadoop APIs and learn = how to run these jobs, the logic in the Map job is irrelevant.
2. The code snippet is below with just the APIs = (which I believe is causing a problem - PLEASE correct me if I am wrong and= I will post the entire code snippet)
public  
....
....
public static class JobOrganizerMapper extends= MapReduceBase implements Mapper<String, String, = String, String> {
 
@Override
public void<= FONT size=3D2> map(String sourceKey, String sourceValue, OutputCollector<= ;String, String> outputC,
Reporter reporter) throws IOException {<= /FONT>
...
...
}
 
}
 
Exception:
 
hduser@utester-VirtualBox:/usr/local/hadoop/bin$ /usr/local/hadoop/bin/hadoop jar ~/HadoopCodeProjectsFolder/JobOrga= nizerMapRedProject/11182012/HadoopMapRedProject.jar org.u.hadoopmapred.JobO= rganizer
Warning: $HADOOP_HOME is deprecated.
12/11/18 16:36:22 WARN mapred.JobClient: Use GenericOptionsParser for = parsing the arguments. Applications should implement Tool for the same.
= 12/11/18 16:36:22 INFO util.NativeCodeLoader: Loaded the native-hadoop libr= ary
12/11/18 16:36:22 WARN snappy.LoadSnappy: Snappy native library not = loaded
12/11/18 16:36:22 INFO mapred.FileInputFormat: Total input paths = to process : 1
12/11/18 16:36:22 INFO mapred.JobClient: Running job: job= _201211181608_0002
12/11/18 16:36:23 INFO mapred.JobClient:  map 0%= reduce 0%
12/11/18 16:36:42 INFO mapred.JobClient: Task Id : attempt_20= 1211181608_0002_m_000000_0, Status : FAILED
java.lang.ClassCastException= : org.apache.hadoop.io.LongWritable cannot be cast to java.lang.String
&= nbsp;at org.u.hadoopmapred.JobOrganizer$JobOrganizerMapper.map(JobOrganizer= .java:1)
 at org.apache.hadoop.mapred.MapRunner.run(MapRunner.java:= 50)
 at org.apache.hadoop.mapred.MapTask.runOldMapper(MapTask.java:436)
 
 
The Mapper Interface as per the javadoc is: Interface M= apper <K1, V1, K2, V2> and its map function is: map(K1 key, V1 value,= OutputCollector<K2, V2> output, Reporter). I wanted to paramete= rize K1, V1, K2, V2 to all be String. Is something wrong in the way I am th= inking? Is this what is wrong? I have found similar questions on the intern= et but the asnwers did not clarify how I am breaking the Mapper contract (I= did not have any compile errors - just a runtime error).
 
 
 
Thanks <= /DIV>
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