From fa08cb4ee79e77f47177c9713b31d52905acbaf3 Mon Sep 17 00:00:00 2001
From: Anthony Yeh <enisoc@google.com>
Date: Fri, 18 Nov 2016 16:10:05 -0800
Subject: [PATCH] Clone from previous peer instead of from master.
---
.../mysql-statefulset.yaml | 43 +++++++++++++------
1 file changed, 29 insertions(+), 14 deletions(-)
diff --git a/docs/tutorials/replicated-stateful-application/mysql-statefulset.yaml b/docs/tutorials/replicated-stateful-application/mysql-statefulset.yaml
index f4a6c34df8..accefb2fe2 100644
--- a/docs/tutorials/replicated-stateful-application/mysql-statefulset.yaml
+++ b/docs/tutorials/replicated-stateful-application/mysql-statefulset.yaml
@@ -40,9 +40,11 @@ spec:
# Skip the clone if data already exists.\n
[[ -d /var/lib/mysql/mysql ]] && exit 0\n
# Skip the clone on master (ordinal index 0).\n
- [[ `hostname` =~ -0$ ]] && exit 0\n
- # Clone data from master.\n
- ncat --recv-only mysql-0.mysql 3307 | xbstream -x -C /var/lib/mysql\n
+ [[ `hostname` =~ -([0-9]+)$ ]] || exit 1\n
+ ordinal=${BASH_REMATCH[1]}\n
+ [[ $ordinal -eq 0 ]] && exit 0\n
+ # Clone data from previous peer.\n
+ ncat --recv-only mysql-$(($ordinal-1)).mysql 3307 | xbstream -x -C /var/lib/mysql\n
# Prepare the backup.\n
xtrabackup --prepare --target-dir=/var/lib/mysql\n
"],
@@ -92,31 +94,44 @@ spec:
- "-c"
- |
set -ex
+ cd /var/lib/mysql
+
+ # Determine binlog position of cloned data, if any.
+ if [[ -f xtrabackup_slave_info ]]; then
+ # XtraBackup already generated a partial "CHANGE MASTER TO" query
+ # because we're cloning from an existing slave.
+ mv xtrabackup_slave_info change_master_to.sql.in
+ # Ignore xtrabackup_binlog_info in this case (it's useless).
+ rm xtrabackup_binlog_info
+ elif [[ -f xtrabackup_binlog_info ]]; then
+ # We're cloning directly from master. Parse binlog position.
+ [[ `cat xtrabackup_binlog_info` =~ ^(.*?)[[:space:]]+(.*?)$ ]] || exit 1
+ rm xtrabackup_binlog_info
+ echo "CHANGE MASTER TO MASTER_LOG_FILE='${BASH_REMATCH[1]}',\
+ MASTER_LOG_POS=${BASH_REMATCH[2]}" > change_master_to.sql.in
+ fi
# Check if we need to complete a clone by starting replication.
- cd /var/lib/mysql
- if [[ -f xtrabackup_binlog_info ]]; then
- echo "Waiting for mysqld to accept connections"
+ if [[ -f change_master_to.sql.in ]]; then
+ echo "Waiting for mysqld to be ready (accepting connections)"
until mysql -h 127.0.0.1 -e "SELECT 1"; do sleep 1; done
echo "Initializing replication from clone position"
- [[ `cat xtrabackup_binlog_info` =~ ^(.*?)[[:space:]]+(.*?)$ ]] || exit 1
- mv xtrabackup_binlog_info xtrabackup_binlog_info.orig
+ # In case of container restart, attempt this at-most-once.
+ mv change_master_to.sql.in change_master_to.sql.orig
mysql -h 127.0.0.1 <<EOF
- CHANGE MASTER TO
+ $(<change_master_to.sql.orig),
MASTER_HOST='mysql-0.mysql',
MASTER_USER='root',
MASTER_PASSWORD='',
- MASTER_CONNECT_RETRY=10,
- MASTER_LOG_FILE='${BASH_REMATCH[1]}',
- MASTER_LOG_POS=${BASH_REMATCH[2]};
+ MASTER_CONNECT_RETRY=10;
START SLAVE;
EOF
fi
- # Start a server to send backups when requested.
+ # Start a server to send backups when requested by peers.
exec ncat --listen --keep-open --send-only --max-conns=1 3307 -c \
- "xtrabackup --backup --stream=xbstream --host=127.0.0.1 --user=root"
+ "xtrabackup --backup --slave-info --stream=xbstream --host=127.0.0.1 --user=root"
volumeMounts:
- name: data
mountPath: /var/lib/mysql