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  1. Core Server
  2. SERVER-17303

concurrent findAndModify ops with upsert: true can cause a fatal logOp() rollback

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      On that box:

      $ cd /home/buzz
$ sh runt stateEvent --port 37017 -d test5 --numevents 2000000 --posn 100000 --threads 32 --drop --payload 8192

      It will fail 90% of the time somewhere after 3000 and 7000 turns of the crank.

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      On that box: $ cd /home/buzz $ sh runt stateEvent --port 37017 -d test5 --numevents 2000000 --posn 100000 --threads 32 --drop --payload 8192 It will fail 90% of the time somewhere after 3000 and 7000 turns of the crank.

      This is the big IBM X6 box. High perf SSDs on /data/[1-4]:

      [buzz@IDF-IBM-Test-1 ~]$ uname -a
Linux IDF-IBM-Test-1.10gen.cc 2.6.32-431.el6.x86_64 #1 SMP Fri Nov 22 03:15:09 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux
[buzz@IDF-IBM-Test-1 ~]$ cat /etc/redhat-release 
CentOS release 6.6 (Final)
[buzz@IDF-IBM-Test-1 ~]$ df
Filesystem           1K-blocks     Used Available Use% Mounted on
/dev/mapper/vg_idfibmtest1-lv_root
                      51606140 11926496  37058204  25% /
tmpfs                396812172        0 396812172   0% /dev/shm
/dev/sda1               495844    96335    373909  21% /boot
/dev/mapper/vg_idfibmtest1-lv_home
                     231167100   832892 218591592   1% /home
/dev/md1             768924576 20997468 708868020   3% /data/1
/dev/md2             768924576 10687204 719178284   2% /data/2
/dev/md3             768924576   201440 729664048   1% /data/3
/dev/md4             768924576  3242900 726622588   1% /data/4

      Using rc8 with WiredTiger. No special startup options:

      numactl --interleave=all /home/buzz/3.0.0-rc8/bin/mongod --storageEngine=wiredTiger --port 37017 --dbpath /data/4/data0/db0 --logpath /tmp/mongo0.log --fork

      Test program starts 32 threads. Each thread randomly looks for a "position" Pn where 0 <= n < 10000, e.g. P433 in the currentPos collection. findAndModify is used to logically reserve the item. A small event record is inserted to the events collection, the fetched item is "copied" to the historicPos collection, and then currentPos is findAndModify()d with updated info. The find-insert-insert-update sequence we'll call a turn of the crank.

      Trouble starts

        1. mongo0.log
          1.72 MB
          Buzz Moschetti
        2. rc9.log
          357 kB
          Buzz Moschetti

            Assignee:
            david.storch@mongodb.com David Storch
            Reporter:
            buzz.moschetti Buzz Moschetti
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              Created:
              Updated:
              Resolved: