Oops - we just hit 10 writers.

On 11/09/2016 08:54 AM, Stephen Clark wrote:
Hi Paolo,

Thanks for the response. Do you see anything in our confguration
that I could adjust to mitigate the situation.

We never reach 10 sql writers.

Would increasing the any of these help?
 sql_refresh_time: 60
sql_optimize_clauses: true
!sql_history: 5m
sql_history: 1m
sql_history_roundoff: m


On 11/09/2016 07:58 AM, Paolo Lucente wrote:
Hi Steve,

You are experiencing a few connected problems, i guess. The root issue
should be that the PostgreSQL database is not coping with the insert or
update rate and/or with the size of the dataset.

The list of plugins you see there are, in fact, all DB writers. They are
queued up, waiting for the table they want to write to will unlock. What
typically happens, wrt the seg fault, is that each of these processes
does take some memory; you stack many of them, memory goes away; you try
to stack more, they go seg fault due to lack of system resources. You
can prevent that lowering the amoung of writers allowed to stack up, by
default 10, via sql_max_writers.

Finally, it is normal that the active DB writer can take 100% CPU in order
to dump all its data to the backend. On shortage of system resources the
situation can get unstabe and you may see multiple processes in such
state as they start competing with kernel, ie. swap, etc.


On Tue, Nov 08, 2016 at 03:34:57PM -0500, Stephen Clark wrote:

I am having a problem with nfacctd getting way behind with ver 1.5.3
Everything is ok until I add a server that is sending a lot of netflows
then things start bogging down. I see the nfacctd plugins using 100% cpu using top.

Then I start getting seg faults:
Nov  8 15:28:01 netflow2 kernel: nfacctd[14296]: segfault at 0 ip
000000000046d588 sp 00007fffe95e72c0 error 4 in

11389 ?        R      8:15 nfacctd: pgsql Plugin -- DB Writer [default]
11993 ?        R      7:11 nfacctd: pgsql Plugin -- DB Writer [default]
12229 ?        R      6:14 nfacctd: pgsql Plugin -- DB Writer [default]
12372 ?        R      5:15 nfacctd: pgsql Plugin -- DB Writer [default]
12435 ?        R      4:14 nfacctd: pgsql Plugin -- DB Writer [default]
12678 ?        R      3:17 nfacctd: pgsql Plugin -- DB Writer [default]
13187 ?        R      2:17 nfacctd: pgsql Plugin -- DB Writer [default]
13499 ?        R      1:13 nfacctd: pgsql Plugin -- DB Writer [default]
13711 ?        R      0:24 nfacctd: pgsql Plugin -- DB Writer [default]

daemonize: true
debug: false
pidfile: /var/run/nfacctd.pid
syslog: daemon

pre_tag_map: /etc/pmacct/my.pretag.map

nfacctd_disable_checks: true

nfacctd_time_new: false

aggregate: tag, src_host, dst_host, src_port, dst_port, proto, tos

!plugin_pipe_size: 8192000
!plugin_buffer_size: 8192
plugin_pipe_size: 4096000
plugin_buffer_size: 4096

plugins: pgsql

sql_table: netflow
sql_data: typed

sql_dont_try_update: true
sql_use_copy: true
sql_db: pmacct
sql_passwd: ******
sql_user: pmacct

sql_refresh_time: 60
sql_optimize_clauses: true

sql_history: 1m
sql_history_roundoff: m
sql_recovery_logfile: /var/lib/pmacct/recovery_log

sql_preprocess:  fsrc=200000

sql_locking_style: row
sql_cache_entries: 299999

imt_buckets: 65537
imt_mem_pools_size: 1024000

nfacctd_port: 2055



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