[Info-ingres] What does XA_END mean in the SC930 log?

[Roy Hann]

Hmmm.

The reason I was asking is because I am seeing stuff like this:

EQY:1513854718/299769010:1::50:(232:0):0:1
XA_END:1513854718/620735450:XID(00020005:29:36:00000000:00000000:0000FFFF:0AD01E32:BD045DF2:5A3A5A00:00008CD9:31000000:00000000:000000FF:FF0AD01E:32BD045D:F25A3A5A:0000008C:DC00000
0:00000000:00000000:XA):00000000:0
EQY:1513854718/620833715:-1::50:(232:0):0:0
XA_PREP:1513854718/655271335:XID(00020005:29:36:00000000:00000000:0000FFFF:0AD01E32:BD045DF2:5A3A5A00:00008CD9:31000000:00000000:000000FF:FF0AD01E:32BD045D:F25A3A5A:0000008C:DC0000
00:00000000:00000000:XA):00000000:0
EQY:1513854718/655330225:-1::50:(232:31):0:0
XA_COMM:1513854718/659405680:XID(00020005:29:36:00000000:00000000:0000FFFF:0AD01E32:BD045DF2:5A3A5A00:00008CD9:31000000:00000000:000000FF:FF0AD01E:32BD045D:F25A3A5A:0000008C:DC0000
00:00000000:00000000:XA):00000000:0
EQY:1513854718/659471260:-1::50:(232:31):0:0

The thing I'm focussing on is the last field of the EQY record, which
is the transaction state indicator (something I added at one of the
sprints a couple of years ago).

The first EQY shows there is a transaction in progress; the indicator
is 1. We then see an XA_END--as a result of who-knows-what (I don't do
JDBC)--then the following EQY record shows the transaction has
ended because the state indicator is 0.

If that is the preamble to a 2PC commit then something is broken
because the participant has already committed or rolled back before
voting.

I am trying to decide if the customer's application is misbehaving. If
their application is expected/required to do whatever logs an XA_END
then maybe the problem is something else.

Roy


Thursday, December 21, 2017, 8:22:06 PM, you wrote:

> As far as I can recall, XA_END is something that happens prior to
> preparing and committing the distributed connection.  The sequence is basically:
>  
>                 XA_START
>                 XA_END
>                 XA_PREPARE
>                 XA_COMMIT
>  
>  
>  
> XA_END is issued when the XA Transaction Manager calls
> javax.transaction.xa.XAResource.end() – not that it will help you
> much.  Our JdbcXAConn class implements the XAConnection and
> XAResource interfaces and is controlled by a JDBC connection  pool
> manager and XA Transaction Manager.  What actions drive those
> resources is a bit of a mystery to me.
>
> Gordy
>  
> From: Karl and Betty Schendel [mailto:schendel at kbcomputer.com]
>  Sent: Thursday, December 21, 2017 9:21 AM
>  To: Gordon Thorpe <Gordon.Thorpe at actian.com>
>  Subject: Fwd: [Info-ingres] What does XA_END mean in the SC930 log?
>    
>  
>  
> Hi Gordy,
>  don't know if you still see info-ingres questions...
>  I can sort of answer the first one, but XA in general is a black box to me.
>  
>  Karl
>  
>  
 >> Begin forwarded message:
 >> 
 >> From: Roy Hann <specially at processed.almost.meat>
 >> Subject: [Info-ingres] What does XA_END mean in the SC930 log?
 >> Date: December 21, 2017 at 11:54:33 AM EST
 >> To: info-ingres at lists.planetingres.org
 >> 
 >> When I see an XA_END in the trace log, what will have happened to cause
 >> that? Is there a JDBC XAconnection method to explicitly signal the end
 >> of the transaction or is it (somehow) implicit?
 >> 
 >> If there was a transaction open but there was no preceding XA_COMM is
 >> the transaction implicitly committed or rolled back? (I guess it is
 >> committed.)
 >> 
 >> Is whatever it is that causes an XA_END to be logged a legitimate
 >> alternative to explicitly executing the commit method on the session
 >> object (within a 2PC coordinator)?
 >> 
 >> Roy
 >> 
 >> 
 >> _______________________________________________
 >> Info-ingres mailing list
 >> Info-ingres at lists.planetingres.org
 >>  http://lists.planetingres.org/mailman/listinfo/info-ingres
>     



Roy Hann
Rational Commerce Ltd.
T +44 20 8691 2089
"Ingres development, tuning and training experts"