Michael Czajkowski created THRIFT-4858:
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Summary: Java TThreadPoolServer calls TBaseProcesser twice,
erroneously
Key: THRIFT-4858
URL: https://issues.apache.org/jira/browse/THRIFT-4858
Project: Thrift
Issue Type: Bug
Components: Java - Library
Affects Versions: 0.12.0
Environment: Here is some information on my environment and code that
calls Thrift.
Environment: Red Hat Linux 7.6, Java 1.8, Thrift 0.12.0. Both my client and
server are in Java. However, I have also seen this when a Python client calls
the Java server.
Here is what I do to set up the server, my service Iface name is
"AlgorithmRepository" ...
{{TServerTransport transport = new TServerSocket(10202);}}
{{ TProcessor processor = new AlgorithmRepository.Processor<>(this);}}
{{ Args args = new
TThreadPoolServer.Args(transport).processor(processor).inputTransportFactory(new
TFramedTransport.Factory()).outputTransportFactory(new
TFramedTransport.Factory()).protocolFactory(new TBinaryProtocol.Factory());}}
{{ final TServer server = new TThreadPoolServer(args);}}
{{ new Thread(server::serve).start();}}
That last line corresponds to the Thread you see at the bottom of the exception.
It is worth noting we did also set the Input and Output Protocol Factories too
and it had no affect on the result.
We saw on stackoverflow that if you don't have the same Transport type, it will
fail to function. Here is client code that sets this up:
{{TTransport transport = new TFramedTransport(new TSocket(host, port,
socketTimeoutMillis));}}
I'd be happy to share more client code if you felt it was something the client
is doing wrong.
Reporter: Michael Czajkowski
I've spotted an error in using java libthrift that I'd like to call to your
attention. It is in version 0.12.0, but I see it in other versions. I will
comment about the other versions at the end, please read - it may be very
*important* to you.
I create a TThreadPoolServer, and when my client calls a method, the server
spawns off a worker thread and when it gets to this line:
{{if(stopped_ || !processor.process(inputProtocol, outputProtocol)) {}}
{{break;}}
{{ }}}
It will call a TBaseProcessor's process method, which can only return either
True or throw an Exception. In my case, it gets to the very bottom and calls
the ProcessFunction fn properly:
{{fn.process(msg.seqid, in, out, iface);}}
Followed by returning true. However, since the TThreadPoolServer will not
"break" out of the while(true) loop it is in, it will attempt to call the
TBaseProcessor's process method again and this time around I get an exception
when this line is called on TBaseProcessor's process method:
{{TMessage msg = in.readMessageBegin();}}
Exception is:
17844 [pool-6-thread-5] ERROR org.apache.thrift.server.TThreadPoolServer -
Thrift error occurred during processing of message.
{{org.apache.thrift.transport.TTransportException}}
{{ at
org.apache.thrift.transport.TIOStreamTransport.read(TIOStreamTransport.java:132)}}
{{ at org.apache.thrift.transport.TTransport.readAll(TTransport.java:86)}}
{{ at
org.apache.thrift.transport.TFramedTransport.readFrame(TFramedTransport.java:132)}}
{{ at
org.apache.thrift.transport.TFramedTransport.read(TFramedTransport.java:100)}}
{{ at org.apache.thrift.transport.TTransport.readAll(TTransport.java:86)}}
{{ at
org.apache.thrift.protocol.TBinaryProtocol.readAll(TBinaryProtocol.java:425)}}
{{ at
org.apache.thrift.protocol.TBinaryProtocol.readI32(TBinaryProtocol.java:321)}}
{{ at
org.apache.thrift.protocol.TBinaryProtocol.readMessageBegin(TBinaryProtocol.java:225)}}
{{ at org.apache.thrift.TBaseProcessor.process(TBaseProcessor.java:33)}}
{{ at
org.apache.thrift.server.TThreadPoolServer$WorkerProcess.run(TThreadPoolServer.java:318)}}
{{ at
java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)}}
{{ at
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)}}
{{ at java.lang.Thread.run(Thread.java:748)}}
I surmise because my TProtocol in has already sent the bytes (I am using a
TBinaryProtocol) to the process function, there is nothing left to read and
thus we never make it to the next line:
{{ProcessFunction fn = processMap.get(msg.name);}}
For giggles, I decided to remove the ! from the logic, and sure enough it gets
by but it appears to perhaps cause other problems when a client calls a method
with zero parameters (e.g. "ping()").
*Other versions:* So far as I can tell this exact same set up is in java
libthrift 0.9.0, 0.9.1, and 0.9.3.1. However, my Java code works just fine in
those. I only discovered this problem when I went to upgrade my code to Thrift
0.12.0. I honestly can't make sense of why that would be OK in those older
versions but, I've been blissfully unaware of this problem until the upgrade. I
used TThreadPoolServer then as I do now. I figured perhaps something else is
happening in Thrift with my TThreadPoolServer. Finally, I did see the problem
in 0.12.1 and did not test it, though it appears changed in the master branch -
we tried it and it still has errors.
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