For a while now we've sort of anecdotally thought that compression should help with base backups and also that the rsync server is faster than rsync over ssh, so while nothing was happening on our test server, I thought I'd benchmark a few different methods.
Looks like rsync using an rsync server with no compression was fastest, but not by much. Pg_basebackup is right there with rsync using any of the three RC4 ciphers all within a few seconds of one another. Looks like blowfish-cbc comes in next followed by aes128-cbc.
Most interesting is that adding compression quadruples the sync time! That's probably not the case over a slow link, but over gigabit it's definitely the case.
Tests were done with a 93GB PGDATA, gigabit network, linux software 4 disk RAID10 data dir on the first test server copied to linux software 2 disk RAID0 on the second server.
Following are the results:
Following are the results:
Without compression:
time rsync test0::data /data/tmp/test-data/ -avP
real 15m52.221s
user 3m10.257s
sys 4m11.460s
time /usr/pgsql-9.1/bin/pg_basebackup -D /data/tmp/test-data -c fast -h test0 -U postgres
real 16m13.440s
user 0m17.314s
sys 2m18.217s
time rsync -e 'ssh -c arcfour' postgres@test0:/data/9.1/data/ /data/tmp/test-data/ -avP
real 16m13.242s
user 8m32.674s
sys 5m28.312s
time rsync -e 'ssh -c arcfour256' postgres@test0:/data/9.1/data/ /data/tmp/test-data/ -avP
real 16m13.656s
user 8m48.356s
sys 6m7.343s
time rsync -e 'ssh -c arcfour128' postgres@test0:/data/9.1/data/ /data/tmp/test-data/ -avP
real 16m3.947s
user 8m44.627s
sys 6m7.499s
time rsync -e 'ssh -c blowfish-cbc' postgres@test0:/data/9.1/data/ /data/tmp/test-data/ -avP
real 26m22.516s
user 19m16.038s
sys 8m45.046s
time rsync -e 'ssh -c aes128-cbc' postgres@test0:/data/9.1/data/ /data/tmp/test-data/ -avP
real 29m30.785s
user 27m31.919s
sys 6m5.154s
time rsync -e 'ssh' postgres@test0:/data/9.1/data/ /data/tmp/test-data/ -avP
real 30m50.301s
user 24m10.951s
sys 9m13.090s
time rsync -e 'ssh -c aes256-ctr' postgres@test0:/data/9.1/data/ /data/tmp/test-data/ -avP
real 38m23.789s
user 31m36.011s
sys 8m39.210s
Our Best Performers With Compression:
time rsync -e 'ssh -c arcfour' postgres@test0:/data/9.1/data/ /data/tmp/test-data/ -avPz
real 62m31.933s
user 14m48.752s
sys 2m42.412s
time rsync test0::data /data/tmp/test-data/ -avPz
real 62m53.699s
user 6m42.846s
sys 1m44.357s![]()
Looks like rsync using an rsync server with no compression was fastest, but not by much. Pg_basebackup is right there with rsync using any of the three RC4 ciphers all within a few seconds of one another. Looks like blowfish-cbc comes in next followed by aes128-cbc.
Most interesting is that adding compression quadruples the sync time! That's probably not the case over a slow link, but over gigabit it's definitely the case.
Tests were done with a 93GB PGDATA, gigabit network, linux software 4 disk RAID10 data dir on the first test server copied to linux software 2 disk RAID0 on the second server.
Following are the results:
Following are the results:
Without compression:
time rsync test0::data /data/tmp/test-data/ -avP
real 15m52.221s
user 3m10.257s
sys 4m11.460s
time /usr/pgsql-9.1/bin/pg_basebackup -D /data/tmp/test-data -c fast -h test0 -U postgres
real 16m13.440s
user 0m17.314s
sys 2m18.217s
time rsync -e 'ssh -c arcfour' postgres@test0:/data/9.1/data/ /data/tmp/test-data/ -avP
real 16m13.242s
user 8m32.674s
sys 5m28.312s
time rsync -e 'ssh -c arcfour256' postgres@test0:/data/9.1/data/ /data/tmp/test-data/ -avP
real 16m13.656s
user 8m48.356s
sys 6m7.343s
time rsync -e 'ssh -c arcfour128' postgres@test0:/data/9.1/data/ /data/tmp/test-data/ -avP
real 16m3.947s
user 8m44.627s
sys 6m7.499s
time rsync -e 'ssh -c blowfish-cbc' postgres@test0:/data/9.1/data/ /data/tmp/test-data/ -avP
real 26m22.516s
user 19m16.038s
sys 8m45.046s
time rsync -e 'ssh -c aes128-cbc' postgres@test0:/data/9.1/data/ /data/tmp/test-data/ -avP
real 29m30.785s
user 27m31.919s
sys 6m5.154s
time rsync -e 'ssh' postgres@test0:/data/9.1/data/ /data/tmp/test-data/ -avP
real 30m50.301s
user 24m10.951s
sys 9m13.090s
time rsync -e 'ssh -c aes256-ctr' postgres@test0:/data/9.1/data/ /data/tmp/test-data/ -avP
real 38m23.789s
user 31m36.011s
sys 8m39.210s
Our Best Performers With Compression:
time rsync -e 'ssh -c arcfour' postgres@test0:/data/9.1/data/ /data/tmp/test-data/ -avPz
real 62m31.933s
user 14m48.752s
sys 2m42.412s
time rsync test0::data /data/tmp/test-data/ -avPz
real 62m53.699s
user 6m42.846s
sys 1m44.357s
