Terminating a connection result in Encoding error and indefinite block statement.

[meetme2meat]

The issue is related to pg_jruby (0.17.1 java) Tested with JRuby 9.0.5.0 and ...

java version "1.8.0_144"
Java(TM) SE Runtime Environment (build 1.8.0_144-b01)
Java HotSpot(TM) 64-Bit Server VM (build 25.144-b01, mixed mode)

Terminating the Postgres connection result in (encoding) error type different from the one obtained in ruby pg.(first time).

Re-Running the SQL statement on already terminated connection result in indefinite blocking again a behaviour much different from ruby pg.

Ruby PG behaviour

 require 'pg'
 conn = PG.connect(dbname: 'postgres', user: 'postgres')
 ## Use either `pg_terminate_backend` or `kill` command to terminate the connection.
 conn.exec('select 1') ## 1 st time
 PG::UnableToSend: erver closed the connection unexpectedly
 	This probably means the server terminated abnormally
 	before or while processing the request.
 
 conn.exec('select 1`) ## 2nd time same error type no blocking.
 PG::UnableToSend: no connection to the server
 

Jruby pg behaviour

require 'pg'
conn = PG.connect(dbname: 'postgres', user: 'postgres')
## Use either `pg_terminate_backend` or `kill` command to terminate the connection.
conn.exec('select 1') ## 1 st time
Java::JavaLang::NoSuchMethodError: org.jruby.RubyEncoding.newEncoding(Lorg/jruby/Ruby;Lorg/jcodings/Encoding;)Lorg/jruby/RubyEncoding;
	from org.jruby.pg.Connection.newPgErrorCommon(Connection.java:1434)
	from org.jruby.pg.Connection.newPgError(Connection.java:1450)
	from org.jruby.pg.Connection.exec(Connection.java:544)
	from org.jruby.pg.Connection$INVOKER$i$0$2$exec_DBG.call(Connection$INVOKER$i$0$2$exec_DBG.gen)
	from org.jruby.internal.runtime.methods.DynamicMethod.call(DynamicMethod.java:201)
	from org.jruby.internal.runtime.methods.DynamicMethod.call(DynamicMethod.java:197)
	from org.jruby.runtime.callsite.CachingCallSite.cacheAndCall(CachingCallSite.java:313)
	from org.jruby.runtime.callsite.CachingCallSite.call(CachingCallSite.java:163)
	from org.jruby.ir.interpreter.InterpreterEngine.processCall(InterpreterEngine.java:316)
	from org.jruby.ir.interpreter.StartupInterpreterEngine.interpret(StartupInterpreterEngine.java:77)
	from org.jruby.ir.interpreter.Interpreter.INTERPRET_EVAL(Interpreter.java:122)
	from org.jruby.ir.interpreter.Interpreter.evalCommon(Interpreter.java:177)
	from org.jruby.ir.interpreter.Interpreter.evalWithBinding(Interpreter.java:202)
	from org.jruby.RubyKernel.evalCommon(RubyKernel.java:1009)
	from org.jruby.RubyKernel.eval19(RubyKernel.java:976)
	from org.jruby.RubyKernel$INVOKER$s$0$3$eval19_DBG.call(RubyKernel$INVOKER$s$0$3$eval19_DBG.gen)
... 104 levels...
	from org.jruby.runtime.callsite.CachingCallSite.cacheAndCall(CachingCallSite.java:313)
	from org.jruby.runtime.callsite.CachingCallSite.call(CachingCallSite.java:163)
	from org.jruby.ir.interpreter.InterpreterEngine.processCall(InterpreterEngine.java:316)
	from org.jruby.ir.interpreter.StartupInterpreterEngine.interpret(StartupInterpreterEngine.java:77)
	from org.jruby.ir.interpreter.Interpreter.INTERPRET_ROOT(Interpreter.java:112)
	from org.jruby.ir.interpreter.Interpreter.execute(Interpreter.java:99)
	from org.jruby.ir.interpreter.Interpreter.execute(Interpreter.java:35)
	from org.jruby.ir.IRTranslator.execute(IRTranslator.java:42)
	from org.jruby.Ruby.runInterpreter(Ruby.java:848)
	from org.jruby.Ruby.runInterpreter(Ruby.java:853)
	from org.jruby.Ruby.runNormally(Ruby.java:752)
	from org.jruby.Ruby.runFromMain(Ruby.java:569)
	from org.jruby.Main.doRunFromMain(Main.java:415)
	from org.jruby.Main.internalRun(Main.java:310)
	from org.jruby.Main.run(Main.java:239)
	from org.jruby.Main.main(Main.java:201)

Running the SQL statement 2nd time result indefinite block of the running program.

conn.execute('select 1')
## the code block no timeout happens.

If the connection is closed by the client then the JRuby pg End result is same as Ruby pg.

[headius]

That looks like jruby-pg was compiled against a version of JRuby that had that "RubyEncoding.newEncoding" method. I have not determined where that method came from or where it went, but it doesn't appear to exist in the jruby-9.1 branch.

We'll need to try recompiling jruby-pg against a current JRuby and see why it's using this method. I don't think it's the right thing to be calling in any case.

[meetme2meat]

Thanks, @headius. I'll check the above behaviour with JRuby-9.1 branch
But .. can I do something on this?

We'll need to try recompiling jruby-pg against a current JRuby and see why it's using this method. I don't think it's the right thing to be calling in any case.

[headius]

You could try to build pg against a recent JRuby. I have not built it in a while and I'm suffering from jet lag so I can't help you do that tonight, but perhaps tomorrow :-)

[meetme2meat]

@headius Tested this under JRuby-9.1.5.0 Same result. Other than the Encoding issue the PG client seem to block execution for an indefinite period when an exec statement is triggered by a terminating connection.

[headius]

@meetme2meat 9.1.5.0 is still 10 releases behind current JRuby. Are you having trouble installin 9.1.15.0?

[meetme2meat]

@headius No trouble installing jruby 9.1.5.0 as such but when tested the above behaviour under 9.1.5.0 the Java::JavaLang::NoSuchMethodError error seem to persist.

Let me know If I fail to understand something your last comment.

[headius]

I'm sorry, you are still saying "9.1.5.0" when I am saying "9.1.15.0". Let's make this easier: please install JRuby 9.1.16.0, which is now the current release 😄