After applying that commit 22e04dc12df9e0577ba93a75dbef160c8c1ed258, the...

After applying that commit 22e04dc12df9e0577ba93a75dbef160c8c1ed258, the master will block when the standby master is down.

There are a couple things that need to be done to unblock the master.
1. Run gpinitstandby -n to start the standby master back up.
2. Run psql postgres -c "ALTER SYSTEM SET synchronous_standby_names = '';" and reload the master segment.

Note that the ALTER SYSTEM SET has to be called again to set synchronous_standby_names back to '*' (and master config reloaded) to enable synchronous replication again.
Thoughts are to make it 1 step combined into gpinitstandby -n instead of documenting a multi-step process.

What this commit is just to make it 1 step combined into gpinitstandby -n.
Co-authored-by: NNing Yu <nyu@pivotal.io>

gpMgmt/bin/gpinitstandby

@@ -338,6 +338,19 @@ def check_and_start_standby():
                            standby.port,
                            standby.dbid,
                            array.getNumSegmentContents())
+    # set synchronous_standby_names to '*'
+    cmd = gp.GpAddConfigScript('master',
+                               array.master.datadir,
+                               'synchronous_standby_names',
+                               value="'*'",
+                               removeonly=False,
+                               ctxt=gp.REMOTE,
+                               remoteHost=array.master.hostname,
+                               autoconf=True)
+    cmd.run(validateAfter=True)
+    # make it effective
+    pg.ReloadDbConf.local('pg_ctl reload', array.master)
+
     logger.info("Successfully started standby master")
 
 #-------------------------------------------------------------------------

gpMgmt/bin/gppylib/commands/gp.py

@@ -976,7 +976,7 @@ class GpCatVersionDirectory(Command):
 
 #-----------------------------------------------
 class GpAddConfigScript(Command):
-    def __init__(self, name, directorystring, entry, value=None, removeonly=False, ctxt=LOCAL, remoteHost=None):
+    def __init__(self, name, directorystring, entry, value=None, removeonly=False, ctxt=LOCAL, remoteHost=None, autoconf=False):
         cmdStr="echo '%s' | $GPHOME/sbin/gpaddconfig.py --entry %s" % (directorystring, entry)
         if value:
             # value will be encoded and unencoded in the script to protect against shell interpretation
@@ -984,6 +984,8 @@ class GpAddConfigScript(Command):
             cmdStr = cmdStr + " --value '" + value + "'"
         if removeonly:
             cmdStr = cmdStr + " --removeonly "
+        if autoconf:
+            cmdStr = cmdStr + " --autoconf "
 
         Command.__init__(self,name,cmdStr,ctxt,remoteHost)
 

gpMgmt/sbin/gpaddconfig.py

@@ -33,6 +33,7 @@ def parseargs():
     parser.add_option('--entry', type='string')
     parser.add_option('--value', type='string')
     parser.add_option('--removeonly', action='store_true')
+    parser.add_option('--autoconf', action='store_true')
     parser.set_defaults(removeonly=False)
 
     # Parse the command line arguments
@@ -61,7 +62,10 @@ while line:
 
     directory = line.rstrip()
 
-    filename = directory + "/postgresql.conf"
+    if options.autoconf:
+        filename = directory + "/postgresql.auto.conf"
+    else:
+        filename = directory + "/postgresql.conf"
     if not os.path.exists(filename):
         raise Exception("path does not exist" + filename)