2015-12-02

• Replace lzop with xz in log compression cron jobs on DSpace Test—it uses less space:

# cd /home/dspacetest.cgiar.org/log
# ls -lh dspace.log.2015-11-18*
-rw-rw-r-- 1 tomcat7 tomcat7 2.0M Nov 18 23:59 dspace.log.2015-11-18
-rw-rw-r-- 1 tomcat7 tomcat7 387K Nov 18 23:59 dspace.log.2015-11-18.lzo
-rw-rw-r-- 1 tomcat7 tomcat7 169K Nov 18 23:59 dspace.log.2015-11-18.xz

• I had used lrzip once, but it needs more memory and is harder to use as it requires the lrztar wrapper
• Need to remember to go check if everything is ok in a few days and then change CGSpace
• CGSpace went down again (due to PostgreSQL idle connections of course)
• Current database settings for DSpace are db.maxconnections = 30 and db.maxidle = 8, yet idle connections are exceeding this:

$ psql -c 'SELECT * from pg_stat_activity;' | grep cgspace | grep -c idle
39

• I restarted PostgreSQL and Tomcat and it’s back
• On a related note of why CGSpace is so slow, I decided to finally try the pgtune script to tune the postgres settings:

# apt-get install pgtune
# pgtune -i /etc/postgresql/9.3/main/postgresql.conf -o postgresql.conf-pgtune
# mv /etc/postgresql/9.3/main/postgresql.conf /etc/postgresql/9.3/main/postgresql.conf.orig 
# mv postgresql.conf-pgtune /etc/postgresql/9.3/main/postgresql.conf

• It introduced the following new settings:

default_statistics_target = 50
maintenance_work_mem = 480MB
constraint_exclusion = on
checkpoint_completion_target = 0.9
effective_cache_size = 5632MB
work_mem = 48MB
wal_buffers = 8MB
checkpoint_segments = 16
shared_buffers = 1920MB
max_connections = 80

• Now I need to go read PostgreSQL docs about these options, and watch memory settings in munin etc
• For what it’s worth, now the REST API should be faster (because of these PostgreSQL tweaks):

$ curl -o /dev/null -s -w %{time_total}\\n https://cgspace.cgiar.org/rest/handle/10568/32802?expand=all
1.474
$ curl -o /dev/null -s -w %{time_total}\\n https://cgspace.cgiar.org/rest/handle/10568/32802?expand=all
2.141
$ curl -o /dev/null -s -w %{time_total}\\n https://cgspace.cgiar.org/rest/handle/10568/32802?expand=all
1.685
$ curl -o /dev/null -s -w %{time_total}\\n https://cgspace.cgiar.org/rest/handle/10568/32802?expand=all
1.995
$ curl -o /dev/null -s -w %{time_total}\\n https://cgspace.cgiar.org/rest/handle/10568/32802?expand=all
1.786

• Last week it was an average of 8 seconds… now this is ¹⁄₄ of that