COMMAND NAME: gpactivatestandby 

Activates a standby coordinator host and makes it the active coordinator for the 
Greenplum Database system. 


*****************************************************
SYNOPSIS
*****************************************************
 
gpactivatestandby -d <standby_coordinator_datadir> [-f] [-a] [-q] 
  [-l <logfile_directory>] 

gpactivatestandby -? | -h | --help 

gpactivatestandby -v 


*****************************************************
DESCRIPTION
***************************************************** 

The gpactivatestandby utility activates a backup, standby coordinator host 
and brings it into operation as the active coordinator instance for a 
Greenplum Database system. The activated standby coordinator effectively 
becomes the Greenplum Database coordinator, accepting client connections on 
the coordinator port. 

When you initialize a standby coordinator, the default is to use the same 
port as the active coordinator. For information about the coordinator port for the 
standby coordinator, see gpinitstandby. 

You must run this utility from the coordinator host you are activating, not 
the failed coordinator host you are disabling. Running this utility assumes 
you have a standby coordinator host configured for the system (see 
gpinitstandby). 

The utility will perform the following steps: 

* Stops the synchronization process (walreceiver) on the standby coordinator 

* Updates the system catalog tables of the standby coordinator using the logs 

* Activates the standby coordinator to be the new active coordinator for the 
  system 

* Restarts the Greenplum Database system with the new coordinator host 

A backup, standby Greenplum coordinator host serves as a 'warm standby' in 
the event of the primary Greenplum coordinator host becoming non-operational. 
The standby coordinator is kept up to date by transaction log replication 
processes (the walsender and walreceiver), which run on the primary 
coordinator and standby coordinator hosts and keep the data between the primary 
and standby coordinator hosts synchronized. 

If the primary coordinator fails, the log replication process is shutdown, 
and the standby coordinator can be activated in its place by using the 
gpactivatestandby utility. Upon activation of the standby coordinator, the 
replicated logs are used to reconstruct the state of the Greenplum 
coordinator host at the time of the last successfully committed transaction. 

In order to use gpactivatestandby to activate a new primary coordinator host, 
the coordinator host that was previously serving as the primary coordinator cannot 
be running. The utility checks for a postmaster.pid file in the data 
directory of the disabled coordinator host, and if it finds it there, it will 
assume the old coordinator host is still active. In some cases, you may need 
to remove the postmaster.pid file from the disabled coordinator host data 
directory before running gpactivatestandby (for example, if the disabled 
coordinator host process was terminated unexpectedly). 

After activating a standby coordinator, run ANALYZE to update the database 
query statistics. For example: 

psql dbname -c 'ANALYZE;' 

After you activate the standby coordinator as the primary coordinator, the 
Greenplum Database system no longer has a standby coordinator configured. You 
might want to specify another host to be the new standby with the 
gpinitstandby utility. 


*****************************************************
OPTIONS
*****************************************************

-a

 Do not prompt the user for confirmation. 


-d <standby_coordinator_datadir> 

 The absolute path of the data directory for the coordinator host you are 
 activating. 

 If this option is not specified, gpactivatestandby uses the value 
 specified by the environment variable COORDINATOR_DATA_DIRECTORY of the 
 coordinator host you are activating. 

 If a directory cannot be determined, the utility returns an error. 


-f

 Use this option to force activation of the backup coordinator host. Use this 
 option only if you are sure that the standby and primary coordinator hosts 
 are consistent. 


-l <logfile_directory> 

 The directory to write the log file. Defaults to ~/gpAdminLogs. 


-q

 Run in quiet mode. Command output is not displayed on the screen, but is 
 still written to the log file. 


-v

 Displays the version, status, last updated date, and check sum of this 
 utility. 


-? | -h | --help (help) 

 Displays the online help. 


*****************************************************
EXAMPLES
*****************************************************

Activate the standby coordinator host and make it the active coordinator instance 
for a Greenplum Database system (run from backup coordinator host you are 
activating): 

gpactivatestandby -d /gpdata 


*****************************************************
SEE ALSO
*****************************************************

gpinitsystem, gpinitstandby 

