And you can refer here http://issues.apache.org/jira/browse/PIG-240 People has done some work for this issue although it is still not resolved completely.
On Tue, May 18, 2010 at 12:34 PM, Ashutosh Chauhan <[email protected]> wrote: >> we do have multiple threads, > This is what I suspected from beginning :) > > PigServer is not thread-safe, yet. > > Ashutosh > > On Tue, May 18, 2010 at 12:04, Yonggang Qiao <[email protected]> wrote: >> seems it is a known issue. we do have multiple threads, each thread >> will take one script and new a PigServer to run it... >> >> Thanks, >> Yonggang >> >> On Mon, May 17, 2010 at 6:06 PM, Ashutosh Chauhan >> <[email protected]> wrote: >>> From Yonggang description and code snippet .. it seems to me he is not >>> having multithreaded environment.. there is only one thread and he is >>> creating new PigServer instance in it repeatedly for each query... and >>> since static variables are reset everytime.. this should work... >>> PigServer still doesnt work in multi-threaded environment... >>> >>> Ashutosh >>> >>> On Mon, May 17, 2010 at 18:00, Jeff Zhang <[email protected]> wrote: >>>> Ashutosh, >>>> >>>> Are you sure pig now can work on multi-thread environment ? As I know >>>> pig 0.5 can not work on multi-thread environment even you are create >>>> new PigServer for each pig script. >>>> >>>> >>>> On Tue, May 18, 2010 at 5:43 AM, Ashutosh Chauhan >>>> <[email protected]> wrote: >>>>> if you are creating new instance for each query.. you should be fine.. >>>>> which Pig version are you using ? can you paste the snippet of java >>>>> code where you are creating new pig server instance and then using it >>>>> for a new query ? >>>>> >>>>> Ashutosh >>>>> On Mon, May 17, 2010 at 14:17, Yonggang Qiao <[email protected]> >>>>> wrote: >>>>>> sorry, actually yes. no, we use new instance for each script. >>>>>> >>>>>> On Mon, May 17, 2010 at 2:13 PM, Yonggang Qiao <[email protected]> >>>>>> wrote: >>>>>>> yes. yes. >>>>>>> >>>>>>> On Mon, May 17, 2010 at 2:03 PM, Ashutosh Chauhan >>>>>>> <[email protected]> wrote: >>>>>>>> Are you using PigServer java api to run your Pig queries ? If so, are >>>>>>>> you trying to run multiple queries in different threads against same >>>>>>>> Pig server instance? >>>>>>>> >>>>>>>> Ashutosh >>>>>>>> >>>>>>>> On Mon, May 17, 2010 at 13:57, Yonggang Qiao <[email protected]> >>>>>>>> wrote: >>>>>>>>> Hi, >>>>>>>>> >>>>>>>>> anyone has seen this error before? normally our script runs fine, but >>>>>>>>> sometime recently it began to throw this exception. also usually it >>>>>>>>> will go away if I rerun it. >>>>>>>>> >>>>>>>>> Caused by: java.lang.RuntimeException: Unable to find clone for op >>>>>>>>> Project 4-16 Projections: [9] Overloaded: false >>>>>>>>> at >>>>>>>>> org.apache.pig.impl.logicalLayer.LogicalPlan.clone(LogicalPlan.java:132) >>>>>>>>> at >>>>>>>>> org.apache.pig.impl.logicalLayer.LogicalPlanCloneHelper.<init>(LogicalPlanCloneHelper.java:66) >>>>>>>>> at >>>>>>>>> org.apache.pig.impl.logicalLayer.LogicalPlanCloner.getClonedPlan(LogicalPlanCloner.java:45) >>>>>>>>> at >>>>>>>>> org.apache.pig.impl.logicalLayer.parser.QueryParser.ForEachClause(QueryParser.java:3009) >>>>>>>>> at >>>>>>>>> org.apache.pig.impl.logicalLayer.parser.QueryParser.BaseExpr(QueryParser.java:1314) >>>>>>>>> at >>>>>>>>> org.apache.pig.impl.logicalLayer.parser.QueryParser.Expr(QueryParser.java:893) >>>>>>>>> at >>>>>>>>> org.apache.pig.impl.logicalLayer.parser.QueryParser.Parse(QueryParser.java:682) >>>>>>>>> at >>>>>>>>> org.apache.pig.impl.logicalLayer.LogicalPlanBuilder.parse(LogicalPlanBuilder.java:63) >>>>>>>>> at >>>>>>>>> org.apache.pig.PigServer$Graph.parseQuery(PigServer.java:1017) >>>>>>>>> at >>>>>>>>> org.apache.pig.PigServer$Graph.registerQuery(PigServer.java:967) >>>>>>>>> at org.apache.pig.PigServer.registerQuery(PigServer.java:383) >>>>>>>>> at org.apache.pig.PigServer.registerQuery(PigServer.java:399) >>>>>>>>> at ... >>>>>>>>> >>>>>>>>> Thanks, >>>>>>>>> Yonggang >>>>>>>>> >>>>>>>> >>>>>>> >>>>>> >>>>> >>>> >>>> >>>> >>>> -- >>>> Best Regards >>>> >>>> Jeff Zhang >>>> >>> >> > -- Best Regards Jeff Zhang
