R: SSL Compression doesn't work

Thanks Magnus, now compression works properly using pgsql client.

Da: Magnus Hagander [mailto:magnus(at)hagander(dot)net]
Inviato: venerdì 2 gennaio 2015 16:48
A: Edoardo Innocenti - SDB Information Technology Srl
Cc: pgsql-admin(at)postgresql(dot)org
Oggetto: Re: [ADMIN] SSL Compression doesn't work

On Fri, Jan 2, 2015 at 4:39 PM, Edoardo Innocenti - SDB Information Technology Srl <edoardo(dot)innocenti(at)tech(dot)sdb(dot)it<mailto:edoardo(dot)innocenti(at)tech(dot)sdb(dot)it>> wrote:
Hi,
I try to reduce bandwith use with ssl and compression. I create a test with:

1. CentOS release 6.6 (Final )x86_64

a. openssl-1.0.1e-30.el6_6.4.x86_64

b. kernel-2.6.32-504.1.3.el6.x86_64

2. PostgreSQL 9.3.5

a. postgresql93-libs-9.3.5-1PGDG.rhel6.x86_64

b. postgresql93-contrib-9.3.5-1PGDG.rhel6.x86_64

c. postgresql93-9.3.5-1PGDG.rhel6.x86_64

d. postgresql93-server-9.3.5-1PGDG.rhel6.x86_64

I configure a postgresql with SSL (http://www.postgresql.org/docs/9.3/static/ssl-tcp.htm), with self-signed certificate.
All work fine for SSL, but when I try to use the compression I didn’t find any difference monitoring traffic with tcdump.

These commands has the same network load (~1.1MB)

• psql "user=USER password=PASS host=HOST dbname=postgres sslmode=require sslcompression=1" -c "SELECT lpad('', 1024*1024, 'A');"

• psql "user=USER password=PASS host=HOST dbname=postgres sslmode=require sslcompression=0" -c "SELECT lpad('', 1024*1024, 'A');"

• psql "user=USER password=PASS host=HOST dbname=postgres sslmode=disable" -c "SELECT lpad('', 1024*1024, 'A');"

I believe this is because your distribution has decided to turn of SSL compression by default, and require you to set the OPENSSL_DEFAULT_ZLIB variable to turn it back on. See https://bugzilla.redhat.com/show_bug.cgi?id=857051 and https://rhn.redhat.com/errata/RHSA-2013-0587.html.

You need to set this variable both for the server and the client.

--
Magnus Hagander
Me: http://www.hagander.net/
Work: http://www.redpill-linpro.com/
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