[tahoe-lafs-trac-stream] [tahoe-lafs] #1523: MDMF upload via web-API uses much more memory in the gateway process than updating the same file via SFTP

[tahoe-lafs]

#1523: MDMF upload via web-API uses much more memory in the gateway process than
updating the same file via SFTP
--------------------------------+------------------------------------------
     Reporter:  davidsarah      |      Owner:  davidsarah
         Type:  defect          |     Status:  assigned
     Priority:  major           |  Milestone:  undecided
    Component:  code-frontend-  |    Version:  1.9.0a1
  web                           |   Keywords:  memory tahoe-put performance
   Resolution:                  |
Launchpad Bug:                  |
--------------------------------+------------------------------------------

Comment (by davidsarah):

 I started an introducer, 4 storage servers and a gateway. This time the
 gateway had storage disabled. The encoding parameters of the gateway were
 k=3, happy=1, N=10. Initially the memory usage as measured by {{{ps -O
 rss,vsize -C tahoe}}} (command paths snipped for readability) was:
 {{{
   PID   RSS    VSZ S TTY          TIME COMMAND
 16979 39900 163864 S ?        00:00:01 [...]/tahoe start
 ../grid/introducer
 16989 35788 119252 S ?        00:00:00 [...]/tahoe start ../grid/server1
 23864 35752 119028 S ?        00:00:00 [...]/tahoe start ../grid/server2
 23898 35604 119432 S ?        00:00:00 [...]/tahoe start ../grid/server3
 23919 35952 119576 S ?        00:00:00 [...]/tahoe start ../grid/server4
 24326 43768 175908 S ?        00:00:00 [...]/tahoe start
 }}}

 I ran {{{bin/tahoe put --mutable --mutable-type=mdmf zeros}}}, where
 {{{zeros}}} is a file containing 200000000 zero bytes (190.7 MiB). The
 memory usage of the gateway initially climbed to 1384.5 MiB RSS:
 {{{
   PID   RSS    VSZ S TTY          TIME COMMAND
 16979 39896 163864 S ?        00:00:01 [...]/tahoe start
 ../grid/introducer
 16989 36268 119700 S ?        00:00:00 [...]/tahoe start ../grid/server1
 23864 36276 119720 S ?        00:00:00 [...]/tahoe start ../grid/server2
 23898 36236 119916 S ?        00:00:00 [...]/tahoe start ../grid/server3
 23919 36108 119728 S ?        00:00:00 [...]/tahoe start ../grid/server4
 24326 1417760 1549184 R ?     00:00:14 [...]/tahoe start
 26433  5064  28488 S pts/3    00:00:00 /usr/bin/python bin/tahoe put
 --mutable --mutable-type=mdmf zeros
 26434 30280 100568 S pts/3    00:00:01 [...]/tahoe put --mutable
 --mutable-type=mdmf zeros
 }}}
 and then the memory usage of the storage servers climbed uniformly to
 about 117 MiB RSS each:
 {{{
   PID   RSS    VSZ S TTY          TIME COMMAND
 16979 39688 163864 S ?        00:00:01 [...]/tahoe start
 ../grid/introducer
 16989 120040 203588 D ?       00:00:03 [...]/tahoe start ../grid/server1
 23864 119952 203512 D ?       00:00:03 [...]/tahoe start ../grid/server2
 23898 119924 203804 R ?       00:00:03 [...]/tahoe start ../grid/server3
 23919 119796 203524 D ?       00:00:02 [...]/tahoe start ../grid/server4
 24326 1417252 1549184 S ?     00:00:36 [...]/tahoe start
 26433  5016  28488 S pts/3    00:00:00 /usr/bin/python bin/tahoe put
 --mutable --mutable-type=mdmf zeros
 26434 30196 100568 S pts/3    00:00:01 [...]/tahoe put --mutable
 --mutable-type=mdmf zeros
 }}}
 and then more irregularly to a different amount for each server at the end
 of the command, while the gateway usage dropped to about 746 MiB RSS:
 {{{
   PID   RSS    VSZ S TTY          TIME COMMAND
 16979 38984 163864 S ?        00:00:01 [...]/tahoe start
 ../grid/introducer
 16989 127284 211508 S ?       00:00:06 [...]/tahoe start ../grid/server1
 23864 165436 249888 S ?       00:00:05 [...]/tahoe start ../grid/server2
 23898 204000 288408 S ?       00:00:09 [...]/tahoe start ../grid/server3
 23919 203812 288128 S ?       00:00:09 [...]/tahoe start ../grid/server4
 24326 763624 896564 S ?       00:01:10 [...]/tahoe start
 }}}

 There seems to be quite a severe memory leak, since these figures hadn't
 decreased 20 minutes later.

-- 
Ticket URL: <http://tahoe-lafs.org/trac/tahoe-lafs/ticket/1523#comment:4>
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