From 8fef58405fbac15c0ea93f0d890b114c870de0cc Mon Sep 17 00:00:00 2001
From: Damien Ciabrini <dciabrin@redhat.com>
Date: Wed, 8 Nov 2017 15:19:33 +0100
Subject: [PATCH] galera: recover from empty gvwstate.dat

While running, a galera node keeps track of the last known state of
the cluster in a temporary file gvwstate.dat. This file is normally
deleted once a node is shutdown gracefully.

Some ungraceful shutdowns can leave an empty gvwstate.dat on
disk. This will prevent galera to join the cluster if it is
configured to attempt PC recovery. Removing that file makes the
node fall back to the normal, unoptimized joining process next
time it is restarted.
---
 heartbeat/galera | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/heartbeat/galera b/heartbeat/galera
index ab121a4be..ee8451427 100755
--- a/heartbeat/galera
+++ b/heartbeat/galera
@@ -586,6 +586,17 @@ detect_last_commit()
     local recovery_file_regex='s/.*WSREP\:.*position\s*recovery.*--log_error='\''\([^'\'']*\)'\''.*/\1/p'
     local recovered_position_regex='s/.*WSREP\:\s*[R|r]ecovered\s*position.*\:\(.*\)\s*$/\1/p'
 
+    # codership/galera#354
+    # Some ungraceful shutdowns can leave an empty gvwstate.dat on
+    # disk. This will prevent galera to join the cluster if it is
+    # configured to attempt PC recovery. Removing that file makes the
+    # node fall back to the normal, unoptimized joining process.
+    if [ -f ${OCF_RESKEY_datadir}/gvwstate.dat ] && \
+       [ ! -s ${OCF_RESKEY_datadir}/gvwstate.dat ]; then
+        ocf_log warn "empty ${OCF_RESKEY_datadir}/gvwstate.dat detected, removing it to prevent PC recovery failure at next restart"
+        rm -f ${OCF_RESKEY_datadir}/gvwstate.dat
+    fi
+
     ocf_log info "attempting to detect last commit version by reading ${OCF_RESKEY_datadir}/grastate.dat"
     last_commit="$(cat ${OCF_RESKEY_datadir}/grastate.dat | sed -n 's/^seqno.\s*\(.*\)\s*$/\1/p')"
     if [ -z "$last_commit" ] || [ "$last_commit" = "-1" ]; then