On Thu, Jun 21, 2018 at 8:53 AM, Igor Cicimov < [email protected]> wrote:
> Hi Dmitriy, > > On Thu, Jun 21, 2018 at 12:45 PM, Dmitriy Kuzmin <[email protected]> > wrote: > >> Greetings >> >> I’m using haproxy to load balance readonly queries between redis slaves. >> I want to use health check system to exclude slaves from load balancing, >> that are in a process of sync with master. >> The idea is to look for a string “master_sync_in_progress:1” in response >> to “info replication”. >> > > Is this _exactly_ what is returned? > > >> If this string is found then backend should be marked as down. >> >> I’m trying to use “tcp-check expect ! string” (with exclamation mark [!]) >> to get this working, but backends are permanently down regardless of sync >> status. >> During sync (slave’s response contains “master_sync_in_progress:1”) >> health check status is “L7RSP,TCPCHK matched unwanted content >> 'master_sync_in_progress:1' at step 5”. >> However, when slave’s response contains “master_sync_in_progress:0” (sync >> finished) health check status is “L7TOUT, at step 5 of tcp-check (expect >> string 'master_sync_in_progress:1’)”. >> >> Does negation with exclamation mark (!) work with tcp-check at all? >> >> I’ve observed this behaviour in haproxy 1.5.18, 1.7.11 and 1.8.9 >> >> >> Example configuration: >> >> global >> log 127.0.0.1 local2 >> chroot /var/lib/haproxy >> pidfile /var/run/haproxy.pid >> maxconn 4000 >> user haproxy >> group haproxy >> daemon >> >> defaults >> mode tcp >> log global >> option tcplog >> option dontlognull >> option redispatch >> retries 3 >> timeout http-request 10s >> timeout queue 1m >> timeout connect 10s >> timeout client 1m >> timeout server 1m >> timeout http-keep-alive 10s >> timeout check 10s >> maxconn 3000 >> >> frontend redis_reads_ft >> bind /var/run/haproxy/redis_reads >> use_backend redis_reads_bk >> >> backend redis_reads_bk >> option log-health-checks >> balance roundrobin >> >> option tcp-check >> tcp-check connect >> tcp-check send PING\r\n >> tcp-check expect string +PONG >> tcp-check send info\ replication\r\n >> tcp-check expect ! string >> >> master_sync_in_progress:1 >> > > Try using *rstring* intead of *string*. I that fails too try escaping > the column like "master_sync_in_progress\:1" > > tcp-check send QUIT\r\n >> tcp-check expect string +OK >> >> server sc-redis1_63811 10.10.68.61:63811 check >> server sc-redis1_63812 10.10.68.61:63812 check >> server sc-redis1_63813 10.10.68.61:63813 check >> >> >> Best regards, >> Dmitriy Kuzmin >> > > I'm not sure what string you're trying to match. Could you paste the output of "info replication" somewhere on pastebin or gist? Baptiste
