Re: error - NOTICE: current transaction...MORE DETAIL... - Mailing list pgsql-jdbc

trm

i have been able to successfully avoid the problem for the last 20 minutes
or so...my connection pooling system calls commit() on connections before
returning them to the "available" pool (even if they were already
'committed')...i added a conditional to check whether or not it was already
committed - if it was, i don't run the commit.  this seems to prevent the
"transaction isolation level" exception that always preceded my other
exceptions.  might this apply to your pooling system as well?

thanks
chris

-----Original Message-----
From: T.R.Missner@Level3.com [mailto:T.R.Missner@Level3.com]
Sent: Thursday, September 06, 2001 10:33 AM
To: cmarkiew@commnav.com; pgsql-jdbc@postgresql.org;
pgsql-jdbc-owner@postgresql.org
Subject: RE: [JDBC] error - NOTICE: current transaction...MORE DETAIL...


I really don't understand why this is happening either.
my current guess is that there is something going on
in the way we are reusing connections.  To answer your
question I don't think there is any relationship between the
2 connections just that after the first one is corrupted
I use the second one until it gets corrupted, then
create new ones and start again.  I have to assume
that we are doing something wrong in our use of
these connections and am focusing my effort in that
direction right now.

Sure wish one of the experts would chime in on this.

t.r.

-----Original Message-----
From: chris markiewicz [mailto:cmarkiew@commnav.com]
Sent: Thursday, September 06, 2001 7:17 AM
To: Missner, T. R.; pgsql-jdbc@postgresql.org;
pgsql-jdbc-owner@postgresql.org
Subject: RE: [JDBC] error - NOTICE: current transaction...MORE DETAIL...


tr

things have gotten a little worse...i recently upgraded to postgresql 7.1
and now i am seeing this behavior even WITHOUT large objects.  it happens
much less frequently without LOs, but it still happens.  i never saw this
behavior in 7.0.  are you seeing the same behavior?

i guess i don't understand the following:  right, each connection is a
different process.  so if you use the second connection, why should it fail
too?  it should have no relationship to the first connection, since it is a
different process.
i was discussing this with a co-worker and he suggested that the first
connection might be "spilling" into the second (when you grab the first two
connections, they may inhabit contiguous memory spaces...the first one gets
corrupted and corrupts the second...i admit that i am no unix expert so
while i can picture such a thing, i have no idea whether or not it is
possible.)  anyway, you grab the third connection and it's not corrupt.
does that make any sense?

chris

-----Original Message-----
From: T.R.Missner@Level3.com [mailto:T.R.Missner@Level3.com]
Sent: Wednesday, September 05, 2001 12:45 PM
To: cmarkiew@commnav.com; pgsql-jdbc@postgresql.org;
pgsql-jdbc-owner@postgresql.org
Subject: RE: [JDBC] error - NOTICE: current transaction...MORE DETAIL...


What I have is a connection pool.
I initially grab 2 connections, one primary one secondary.
If the insert fails on the primary connection I try the
secondary, if it fails I simply delete the 2 I have and grab
2 more from the connection pool.  After creating the new ones
I have never seen it fail the first few times which is what
leads me to believe that something in the connection itself is
getting corrupted over time.  Note that each connection is a separate
process in the unix environment.  I believe it is this process that
is getting corrupted note necessarily the java connection wrapper.

Of course this is all guess work right now.  I'll let you know if I
come up with a better solution or are able to determine why
these connections act like they are getting corrupt.



-----Original Message-----
From: chris markiewicz [mailto:cmarkiew@commnav.com]
Sent: Wednesday, September 05, 2001 5:42 AM
To: Missner, T. R.; pgsql-jdbc-owner@postgresql.org
Cc: pgsql-jdbc@postgresql.org
Subject: RE: [JDBC] error - NOTICE: current transaction...MORE DETAIL...


follow-up question - you say that if you get one exception, you try the
insert with another connection...if that doesn't work you delete the
existing connections and get new ones...

i must be missing something - why wouldn't using the second connection
always work?  if you get rid of the offending connection (the first one),
why does the second one have a problem?  or am i confusing your connection
object with the actual connection?

thanks
chris



-----Original Message-----
From: T.R.Missner@Level3.com [mailto:T.R.Missner@Level3.com]
Sent: Tuesday, September 04, 2001 3:35 PM
To: cmarkiew@commnav.com; pgsql-jdbc-owner@postgresql.org
Cc: pgsql-jdbc@postgresql.org
Subject: RE: [JDBC] error - NOTICE: current transaction...MORE DETAIL...


Chris,

I had the same problem on the insert side and thought it went away but
it is back and I am convinced it is related to more than one thread using
the same connection at the same time.  What I have done as a work around
in the interim ( until I write my own connection manager class ) is catch
the exception and try the insert again with another connection.  If it still

fails I delete the connections I have and create new ones and the insert
ALWAYS works after that.  So it appears to me that something is happening
to my connection object that is causing it to get corrupted to some extent.
Once a connection throws this exception it seems much more likely to do so
again which is why I am deleting connections and creating new ones if I have
2 failures back to back.  This isn't the answer you are looking for but
I hoped it might help you think of other ways to troubleshoot your problem.

Since I put this work around in I have been able to run a very high rate
and haven't lost any data on the insert side.  My guess is that these
Fastpath
transactions are very slow compared to non fastpath transactions and it
is easy to use a connection that hasn't finished what it is doing.

I even used a synchronized method to hopefully block on the connection
but this didn't fix the problem either.  Must be some threading going on
in the connection class.  I haven't had the time to go through the code
but I will at some point.

I know someone out there has some insight that could help.

t.r. missner
level(3) communications

-----Original Message-----
From: chris markiewicz [mailto:cmarkiew@commnav.com]
Sent: Tuesday, September 04, 2001 11:40 AM
To: cmarkiew@commnav.com; 'Postgres Jdbc (E-mail)'
Cc: pgsql-jdbc@postgresql.org
Subject: Re: [JDBC] error - NOTICE: current transaction...MORE DETAIL...


hello.  i have some more details on this problem...i found the reference to
calling rollback when you get this sort of error.
(http://fts.postgresql.org/db/mw/msg.html?mid=1030879)... i have started
doing that, but i am still getting the problem.

i have the setup shown below...i've learned that i can usually get around
the fastpath error if i try the query a few times...so i make it call up to
10 times if there is an error...the po.load() call runs the (SELECT
versionid, versionid, versioncomment, versionlabel, creatorid, documentid,
versionorder, datestamp, versioncontent FROM
document_version WHERE versionid = 1034272) query from the last message i
sent (see below)...if that throws an exception, i catch it, rollback, and
contine...i am still seeing the same behavior though...

    public void loadComplex(User user) throws SBHException {
        int iterations = 10;
        try {
            //## TODO:
            //## occasionally get a fastpath exception here...try to
            //## call load() as many as 10 times if there is an exception...
            //## this is here only as a test...
            //## chris markiewicz
            int i = 0;
            boolean exceptionfound = false;
            boolean goodResult = false;
            while (!goodResult && i < iterations) {
                try {
                    i++;
                    dv = (DocumentVersion)po.load(versionid, user);
                    goodResult = true;
                } catch (Exception e) {
                    System.out.println("SBHDocument.loadComplex exception
attempt:"+i);
                    try {po.rollback(user);} catch (Exception e3) {...log
here...}
                    exceptionfound = true;
                    Log.log("SBHDocument.loadComplex attempt:"+i);
                    Log.log("SBHDocument.loadComplex e:"+e);
                    if (i == (iterations - 1)) {
                        throw e;
                    }
                }
            }
            if (exceptionfound) {
                ...log here...
            }
        } catch (TransactionException te) {
            throw te;
        } catch (SBHSecurityException sse) {
            throw sse;
        } catch (SBHException sbe) {
            throw sbe;
        } catch (Exception e) {
            throw new SBHException(e);
        }
    }

here is the log calling that query many times:

DEBUG:  StartTransactionCommand
DEBUG:  query: SELECT versionid, versionid, versioncomment, versionlabel,
creatorid, documentid, versionorder, datestamp, versioncontent FROM
document_version WHERE versionid = 1034277
NOTICE:  current transaction is aborted, queries ignored until end of
transaction block
DEBUG:  CommitTransactionCommand
DEBUG:  StartTransactionCommand
DEBUG:  query: SELECT versionid, versionid, versioncomment, versionlabel,
creatorid, documentid, versionorder, datestamp, versioncontent FROM
document_version WHERE versionid = 1034277
NOTICE:  current transaction is aborted, queries ignored until end of
transaction block
DEBUG:  CommitTransactionCommand
DEBUG:  StartTransactionCommand
DEBUG:  query: SELECT versionid, versionid, versioncomment, versionlabel,
creatorid, documentid, versionorder, datestamp, versioncontent FROM
document_version WHERE versionid = 1034277
NOTICE:  current transaction is aborted, queries ignored until end of
transaction block
DEBUG:  CommitTransactionCommand
DEBUG:  StartTransactionCommand
DEBUG:  query: SELECT versionid, versionid, versioncomment, versionlabel,
creatorid, documentid, versionorder, datestamp, versioncontent FROM
document_version WHERE versionid = 1034277
NOTICE:  current transaction is aborted, queries ignored until end of
transaction block
DEBUG:  CommitTransactionCommand
DEBUG:  StartTransactionCommand
DEBUG:  query: SELECT versionid, versionid, versioncomment, versionlabel,
creatorid, documentid, versionorder, datestamp, versioncontent FROM
document_version WHERE versionid = 1034277
NOTICE:  current transaction is aborted, queries ignored until end of
transaction block
DEBUG:  CommitTransactionCommand

chris


-----Original Message-----
From: pgsql-jdbc-owner@postgresql.org
[mailto:pgsql-jdbc-owner@postgresql.org]On Behalf Of chris markiewicz
Sent: Tuesday, September 04, 2001 11:42 AM
To: Postgres Jdbc (E-mail)
Cc: pgsql-jdbc@postgresql.org
Subject: [JDBC] error - NOTICE: current transaction is aborted, queries
ignored until end of transaction block


Hello.

I have been having problems with postgresql large objects...i have been
searching the archives of this group and i have posted a question or two but
i have so far be unable to resolve the issues.  right now, i have a screen
that loads a few LOs...they occasionally don't make it to the screen.  i see
a couple of different errors in my log files (which i included below).  i
turned on debugging (d2) and i see the following on many of my queries (see
below).

DEBUG:  StartTransactionCommand
DEBUG:  query: SELECT DISTINCT sbhd.timestamp AS "modifydate",
sbhd.versionid AS "versionid", sbhd.documentdescription AS
"sbhdocumentdescription", sbhd.maxversions AS "maxversions", sbhd.documentid
AS "sbhdocumentid", sbhd.hidden AS "hidden", sbhd.documentpath AS
"sbhdocumentpath", sbhd.parentid AS "parentid", sbhd.ownerid AS "ownerid",
sbhd.documentname AS "sbhdocumentname", sbhd.createtimestamp AS "createdate"
FROM document sbhd  WHERE  sbhd.documentpath =
'/cmarkiew/porsche/porsche_speedster.jpg'
DEBUG:  ProcessQuery
DEBUG:  CommitTransactionCommand
DEBUG:  StartTransactionCommand
DEBUG:  query: SELECT versionid, versionid, versioncomment, versionlabel,
creatorid, documentid, versionorder, datestamp, versioncontent FROM
document_version WHERE versionid = 1034272
NOTICE:  current transaction is aborted, queries ignored until end of
transaction block
DEBUG:  CommitTransactionCommand
DEBUG:  StartTransactionCommand
DEBUG:  query: SELECT versionid, versionid, versioncomment, versionlabel,
creatorid, documentid, versionorder, datestamp, versioncontent FROM
document_version WHERE versionid = 1034272
NOTICE:  current transaction is aborted, queries ignored until end of
transaction block
DEBUG:  CommitTransactionCommand

what causes the "current transaction is aborted, queries ignored until end
of transaction block?"  the first query in the above debug block does not
load an LO, but the second one does.  after the second query, seems like all
subsequent have that message...my log file starts getting a bunch of the
following:

No results were returned by the query.
    at org.postgresql.jdbc2.Statement.executeQuery(Statement.java:63)
    at
com.commnav.sbh.framework.persist.JDBCEngine.load(JDBCEngine.java:274)
    at
com.commnav.sbh.framework.persist.PersistenceObject.load(PersistenceObject.j
ava:169)
    at
com.commnav.sbh.framework.documentmanager.SBHDocument.loadComplex(SBHDocumen
t.java:402)
    at
com.commnav.sbh.framework.documentmanager.SBHDocument.getSBHDocument(SBHDocu
ment.java:363)
    at
com.commnav.sbh.servlets.DocumentManager.doPost(DocumentManager.java:201)
    at
com.commnav.sbh.servlets.CommnavServlet.doGet(CommnavServlet.java:170)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:740)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
    at
org.apache.tomcat.core.ServletWrapper.doService(ServletWrapper.java:404)
    at org.apache.tomcat.core.Handler.service(Handler.java:286)
    at
org.apache.tomcat.core.ServletWrapper.service(ServletWrapper.java:372)
    at
org.apache.tomcat.core.ContextManager.internalService(ContextManager.java:79
7)
    at
org.apache.tomcat.core.ContextManager.service(ContextManager.java:743)
    at
org.apache.tomcat.service.http.HttpConnectionHandler.processConnection(HttpC
onnectionHandler.java:210)
    at
org.apache.tomcat.service.TcpWorkerThread.runIt(PoolTcpEndpoint.java:416)
    at
org.apache.tomcat.util.ThreadPool$ControlRunnable.run(ThreadPool.java:498)
    at java.lang.Thread.run(Thread.java:484)
No results were returned by the query.
    at org.postgresql.jdbc2.Statement.executeQuery(Statement.java:63)
    at
com.commnav.sbh.framework.persist.JDBCEngine.load(JDBCEngine.java:274)
    at
com.commnav.sbh.framework.persist.PersistenceObject.load(PersistenceObject.j
ava:169)
    at
com.commnav.sbh.framework.documentmanager.SBHDocument.loadComplex(SBHDocumen
t.java:402)
    at
com.commnav.sbh.framework.documentmanager.SBHDocument.getSBHDocument(SBHDocu
ment.java:363)
    at
com.commnav.sbh.servlets.DocumentManager.doPost(DocumentManager.java:201)
    at
com.commnav.sbh.servlets.CommnavServlet.doGet(CommnavServlet.java:170)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:740)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
    at
org.apache.tomcat.core.ServletWrapper.doService(ServletWrapper.java:404)
    at org.apache.tomcat.core.Handler.service(Handler.java:286)
    at
org.apache.tomcat.core.ServletWrapper.service(ServletWrapper.java:372)
    at
org.apache.tomcat.core.ContextManager.internalService(ContextManager.java:79
7)
    at
org.apache.tomcat.core.ContextManager.service(ContextManager.java:743)
    at
org.apache.tomcat.service.http.HttpConnectionHandler.processConnection(HttpC
onnectionHandler.java:210)
    at
org.apache.tomcat.service.TcpWorkerThread.runIt(PoolTcpEndpoint.java:416)
    at
org.apache.tomcat.util.ThreadPool$ControlRunnable.run(ThreadPool.java:498)
    at java.lang.Thread.run(Thread.java:484)

what should i look for?  can i get other information from logs (i think i
can raise the log level to 3 if it would help).  i can send pieces of code,
but our data layer is pretty abstracted, so i don't know how much that would
help.

finally, an apology.  i started a thread about this issue a few weeks ago
but got pulled onto some other stuff.  i am determined to follow this until
i fix it this time.

i appreciate your help.
chris


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