Re: [TRAP: FailedAssertion] causing server to crash

Hi Craig,

I had done a fresh initdb,the default parameter configuration was used. I
was setting few set of parameters while startup by the below command.

./postgres -d postgres -c shared_buffers=$shared_bufs -N 200 -c
min_wal_size=15GB -c max_wal_size=20GB -c checkpoint_timeout=900 -c
maintenance_work_mem=1GB -c checkpoint_completion_target=0.9 &

Now I have modified the script a bit with Robert's suggestion as below.
Instead of starting it with postgres binary i have set it in conf file and
starting the server with pg_ctl. I am waiting for the results,once the core
dump is generated will share the details.

Test code Snippet :

#Pre condition:
#Create and initialize the database and set the export PGDATA
export PGDATA=/home/centos/PG_sources/postgresql/inst/bin/data
export PGPORT=5432
export
LD_LIBRARY_PATH=/home/centos/PG_sources/postgresql/inst/lib:$LD_LIBRARY_PATH
#for i in "scale_factor shared_buffers time_for_readings no_of_readings
orig_or_patch"
for i in "300 8GB 1800 3"
do
scale_factor=`echo $i | cut -d" " -f1`
shared_bufs=`echo $i | cut -d" " -f2`
time_for_reading=`echo $i | cut -d" " -f3`
no_of_readings=`echo $i | cut -d" " -f4`

# -----------------------------------------------

echo "Start of script for $scale_factor $shared_bufs " >>
/home/centos/test_results.txt

echo "============== $run_bin =============" >>
/home/centos/test_results.txt

for threads in 1 8 16 24 32 40 48 56 64 72 80 88 96 104 112 120 128
#for threads in 8 16
do
#Start taking reading
for ((readcnt = 1 ; readcnt <= $no_of_readings ; readcnt++))
do
echo "================================================" >>
/home/centos/test_results.txt
echo $scale_factor, $shared_bufs, $threads, $threads,
$time_for_reading Reading - ${readcnt} >> /home/centos/test_results.txt
#start server
./pg_ctl -D data -c -l logfile start
#./postgres -d postgres -c shared_buffers=$shared_bufs -N 200 -c
min_wal_size=15GB -c max_wal_size=20GB -c checkpoint_timeout=900 -c
maintenance_work_mem=1GB -c checkpoint_completion_target=0.9 &
sleep 5
#drop and recreate database
./dropdb test
./createdb test
#initialize database
./pgbench -i -s $scale_factor test
sleep 5
# Run pgbench
./pgbench -c $threads -j $threads -T $time_for_reading -M prepared
test >> /home/centos/test_results.txt
sleep 10
./psql -d test -c "checkpoint" >> /home/centos/test_results.txt
./pg_ctl stop
done;
done;

sleep 1

mv /home/centos/test_results.txt
/home/centos/test_results_list_${scale_factor}_${shared_bufs}_rw.txt
done;

Regards,
Neha Sharma

On Thu, Jul 20, 2017 at 11:23 AM, Craig Ringer <craig(at)2ndquadrant(dot)com>
wrote:

> On 19 July 2017 at 20:26, Neha Sharma <neha(dot)sharma(at)enterprisedb(dot)com>
>> wrote:
>>
>>> Hi,
>>>
>>> I am getting FailedAssertion while executing the attached
>>> script.However,I am not able to produce the core dump for the same,the
>>> script runs in background and takes around a day time to produce the
>>> mentioned error.
>>>
>>> "TRAP: FailedAssertion("!(TransactionIdPrecedesOrEquals(oldestXact,
>>> ShmemVariableCache->oldestXid))", File: "clog.c", Line: 683)
>>> 2017-07-19 01:16:51.973 GMT [27873] LOG: server process (PID 28084) was
>>> terminated by signal 6: Aborted
>>> 2017-07-19 01:16:51.973 GMT [27873] DETAIL: Failed process was running:
>>> autovacuum: VACUUM pg_toast.pg_toast_13029 (to prevent wraparound)"
>>>
>>
>>
> What are the starting conditions of your postgres instance? Does your
> script assume a newly initdb'd instance with no custom configuration? If
> not, what setup steps/configuration precede your script run?
>
>
>
>
>
>> well short of the 2-million mark.
>>
>
> Er, billion.
>
> --
> Craig Ringer http://www.2ndQuadrant.com/
> PostgreSQL Development, 24x7 Support, Training & Services
>