How to apply custom filters with Lingual queries on Hbase... #13
Comments
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A quick follow up question: Is your custom HBase Tap a sub-class of the one coming from https://github.com/Cascading/cascading.hbase or a different one ? Taps and Schemes are serialized and sent around on the cluster, meaning that everything in a Tap must be Serializable in one way or the other. An HBase scan object is ultimately a wrapper on top of a TCP socket and those cannot be serialized. What should work is the following: Pass the filters in the constructor of your custom HBaseTap and then create the Scan object in the openForRead() method. Let me know, if that works for you. |
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You'r right it extends teh HbaseTap in cascading.hbase repo. i'l post my findings soon. |
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I think it doesn't like Filter either, it's a Hadoop Writable object and not Serializable.. I'm getting this : cascading.flow.planner.PlannerException: could not build flow from assembly: [unable to pack object: cascading.flow.hadoop.HadoopFlowStep] |
We store operational data into a message store (hbase). I'm trying to take advantage of the custom filters we'v written over this store when a Lingual query is run on it. Otherwise it's a full table scan for each query.
Here is the code i'm trying to run on my hbase instance:
https://gist.github.com/prodeezy/9000271
The approach i'm taking is, I have a custom Tap taht takes in a hbase Scan object. It overrides the openForRead() and create's it's a TableRecordReader with this Scan object applied on it. The code for that method is like so: https://gist.github.com/prodeezy/9000365
I'd like to know if it is possible to do what I'm trying to achieve? If so, is this the right way to do it?
I get the following error curently:
cascading.flow.planner.PlannerException: could not build flow from assembly: [unable to pack object: cascading.flow.hadoop.HadoopFlowStep]
at cascading.flow.planner.FlowPlanner.handleExceptionDuringPlanning(FlowPlanner.java:576)
at cascading.flow.hadoop.planner.HadoopPlanner.buildFlow(HadoopPlanner.java:263)
at cascading.flow.hadoop.planner.HadoopPlanner.buildFlow(HadoopPlanner.java:80)
at cascading.flow.FlowConnector.connect(FlowConnector.java:459)
at cascading.hbase.HBaseStaticTest.testJdbcConnect(HBaseStaticTest.java:104)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:47)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:44)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:271)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:70)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:50)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229)
at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)
at org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:27)
at org.junit.runners.ParentRunner.run(ParentRunner.java:309)
at org.junit.runner.JUnitCore.run(JUnitCore.java:160)
at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:77)
at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:195)
at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:63)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at com.intellij.rt.execution.application.AppMain.main(AppMain.java:120)
Caused by: cascading.flow.FlowException: unable to pack object: cascading.flow.hadoop.HadoopFlowStep
at cascading.flow.hadoop.HadoopFlowStep.pack(HadoopFlowStep.java:195)
at cascading.flow.hadoop.HadoopFlowStep.getInitializedConfig(HadoopFlowStep.java:170)
at cascading.flow.hadoop.HadoopFlowStep.createFlowStepJob(HadoopFlowStep.java:201)
at cascading.flow.hadoop.HadoopFlowStep.createFlowStepJob(HadoopFlowStep.java:69)
at cascading.flow.planner.BaseFlowStep.getFlowStepJob(BaseFlowStep.java:676)
at cascading.flow.BaseFlow.initializeNewJobsMap(BaseFlow.java:1181)
at cascading.flow.BaseFlow.initialize(BaseFlow.java:199)
at cascading.flow.hadoop.planner.HadoopPlanner.buildFlow(HadoopPlanner.java:257)
... 31 more
Caused by: java.io.NotSerializableException: org.apache.hadoop.hbase.client.Scan
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1180)
at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1528)
at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1493)
at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1416)
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1528)
at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1493)
at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1416)
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:346)
at java.util.HashMap.writeObject(HashMap.java:1100)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:975)
at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1480)
at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1416)
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1528)
at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1493)
at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1416)
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1528)
at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1493)
at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1416)
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:346)
at cascading.flow.hadoop.util.JavaObjectSerializer.serialize(JavaObjectSerializer.java:57)
at cascading.flow.hadoop.util.HadoopUtil.serializeBase64(HadoopUtil.java:265)
at cascading.flow.hadoop.HadoopFlowStep.pack(HadoopFlowStep.java:191)
... 38 more
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