Re: streaming replication question

[wd <wd@xxxxxxxxx>]

You can combine warm standby and streaming, we do this in our product database.

When the standby is to far from the master, the slave will try to use restore_command to restore the database(warm standby), when the standby catch up the master, the steaming will working again.

BTW: we use ominipitr.

On Fri, Mar 22, 2013 at 2:32 AM, Roberto Scattini <roberto.scattini@xxxxxxxxx> wrote:

hi list,

i'm installing a streaming replication master-slave setup in ubuntu 12.04 LTS, with postgresql 9.1

the tutorials and the documentation are a very good start point, but i have one question related to some fine grained configurations.

it is said that i should stop the master db in order to make de starting backup, OR run pg_start_backup and keep the archive files for the slave to catch up. if i dont do this, maybe the slave stays far behind the master and the wal_segments arent enough to start the replication. 

if I understand this right, i can "combine" the old "warm standby" configs of archive_command in the master and restore command in the slave to ensure that the slave will have the necessary info to start the replication.

i mean, i can have both configurations enabled?

right now, my streaming replication setup has this configs:

recovery.conf (slave)

-----------------------------------

standby_mode = 'on'

primary_conninfo = 'host=192.168.206.134'

trigger_file = '/var/lib/postgresql/9.1/sgi/sgi.trigger'

restore_command = '/usr/lib/postgresql/9.1/bin/pg_standby -d -k 100 -s 20 -t /var/lib/postgresql/9.1/sgi.trigger /var/lib/postgresql/9.1/archive %f %p'

archive_cleanup_command = '/usr/lib/postgresql/9.1/bin/pg_archivecleanup /var/lib/postgresql/9.1/archive %r'

-----------------------------------

postgresql.conf (master)

-----------------------------------

data_directory = '/var/lib/postgresql/9.1/sgi'

hba_file = '/etc/postgresql/9.1/sgi/pg_hba.conf'

ident_file = '/etc/postgresql/9.1/sgi/pg_ident.conf'

external_pid_file = '/var/run/postgresql/9.1-sgi.pid'

listen_addresses = '*' 

port = 5432               

max_connections = 100

unix_socket_directory = '/var/run/postgresql'

ssl = true 

shared_buffers = 24MB  

wal_level = hot_standby 

archive_mode = on   

archive_command = 'rsync -arv %p 192.168.206.133:/var/lib/postgresql/9.1/archive/%f </dev/null'

archive_timeout = 900

max_wal_senders = 5 

wal_keep_segments = 100 

log_line_prefix = '%t ' 

datestyle = 'iso, mdy'

lc_messages = 'en_US.UTF-8' 

lc_monetary = 'en_US.UTF-8'  

lc_numeric = 'en_US.UTF-8'    

lc_time = 'en_US.UTF-8' 

default_text_search_config = 'pg_catalog.english'

-----------------------------------

thanks,

--
Roberto Scattini