[pgpool-general: 5738] pgpool detected difference of the number of inserted, updated, or deleted tuples. - but there is none?

[Benjamin Firl]

Hi,


sorry to bother you again in such a short time. But as I have written in
"[pgpool-general: 5729] Re: pgpool says its degenerating a backend, but
it does not..." we have some problems with pgpool saying db nodes are
not in sync. I could not find any problems in our code, so I wrote a
little shell script to demonstrate the issue. It uses psql to send
request in parallel  to pgpool with 2 connected db nodes:


/#!/bin/bash//
//
//NUMBER_OF_PROCESSES=2//
//TEST_COUNT=4//
//
//function testDb()//
//{//
//        for i in $(seq 1 $(($TEST_COUNT/$NUMBER_OF_PROCESSES)))//
//        do//
//                echo "$1: $i"//
//                psql -U postgres -p 5433 test -c "DELETE FROM test;
INSERT INTO test VALUES ($RANDOM);"//

//#               psql -U postgres -p 5433 test -c "INSERT INTO test
VALUES ($RANDOM); DELETE FROM test;"//

//#               psql -U postgres -p 5433 test -c "DELETE FROM test;"//
//#               psql -U postgres -p 5433 test -c "INSERT INTO test
VALUES ($RANDOM);"//
//        done//
//}//
//
//for i in $(seq 1 $NUMBER_OF_PROCESSES)//
//do//
//        testDb $i &//
//done//
//
//wait//
//
//echo $(($TEST_COUNT/$NUMBER_OF_PROCESSES*$NUMBER_OF_PROCESSES))
entries tested./


Output is always something like this:

/# ./testDb.sh//
//2: 1//
//1: 1//
//INSERT 0 1//
//2: 2//
//ERROR:  pgpool detected difference of the number of inserted, updated
or deleted tuples. Possible last query was: "DELETE FROM test; INSERT
INTO test VALUES (3469);"//
//HINT:  check data consistency between master and other db node//
//ERROR:  pgpool detected difference of the number of inserted, updated
or deleted tuples. Possible last query was: "DELETE FROM test; INSERT
INTO test VALUES (3469);"//
//HINT:  check data consistency between master and other db node//
//1: 2//
//INSERT 0 1//
//ERROR:  pgpool detected difference of the number of inserted, updated
or deleted tuples. Possible last query was: "DELETE FROM test; INSERT
INTO test VALUES (21477);"//
//HINT:  check data consistency between master and other db node//
//ERROR:  pgpool detected difference of the number of inserted, updated
or deleted tuples. Possible last query was: "DELETE FROM test; INSERT
INTO test VALUES (21477);"//
//HINT:  check data consistency between master and other db node//
//4 entries tested./


If I check manually after the script was running, all nodes have the
same table content. Also if I use one of the other (commented out)
variants in the script, everything works fine.
What is the problem here?


Thanks in advance
Benjamin Firl
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