Add support for Semi-Sync cluster (#20)

Signed-off-by: Mehedi Hasan <[email protected]>

Author: heheh13

init-script/semi_sync_run.sh

@@ -0,0 +1,14 @@
+#!/bin/sh
+
+rm -rf /var/lib/mysql/lost+found
+rm -rf /var/lib/mysql/data/lost+found
+rm -rf /run-scripts/*
+cp /tmp/scripts/* /scripts
+
+if [ ! -d "/var/lib/mysql/raftwal" ]; then
+    mkdir -p /var/lib/mysql/data
+    cd /var/lib/mysql
+    # move all files into the data directory
+    mv $(ls | grep -wv 'data') data/
+fi
+echo "complete initialization."

scripts/run_semi_sync.sh

@@ -0,0 +1,147 @@
+#!/usr/bin/env bash
+args=$@
+USER="$MYSQL_ROOT_USERNAME"
+PASSWORD="$MYSQL_ROOT_PASSWORD"
+localhost=127.0.0.1
+
+function timestamp() {
+    date +"%Y/%m/%d %T"
+}
+
+function log() {
+    local type="$1"
+    local msg="$2"
+    echo "$(timestamp) [$script_name] [$type] $msg"
+}
+
+function retry {
+    local retries="$1"
+    shift
+
+    local count=0
+    local wait=1
+    until "$@"; do
+        exit="$?"
+        if [ $count -lt $retries ]; then
+            log "INFO" "Attempt $count/$retries. Command exited with exit_code: $exit. Retrying after $wait seconds..."
+            sleep $wait
+        else
+            log "INFO" "Command failed in all $retries attempts with exit_code: $exit. Stopping trying any further...."
+            return $exit
+        fi
+        count=$(($count + 1))
+    done
+    return 0
+}
+echo $BASE_NAME
+svr_id=$(($(echo -n "${HOSTNAME}" | sed -e "s/${BASE_NAME}-//g") + 11))
+log "INFO" "server_id =  $svr_id"
+
+mkdir -p /etc/mysql/semi_sync.conf.d/
+echo "!includedir /etc/mysql/semi_sync.conf.d/" >>/etc/mysql/my.cnf
+cat >>/etc/mysql/semi_sync.conf.d/read.cnf <<EOL
+[mysqld]
+datadir=/var/lib/mysql/data
+disabled_storage_engines="MyISAM,BLACKHOLE,FEDERATED,ARCHIVE,MEMORY"
+# General replication settings
+gtid_mode = ON
+enforce_gtid_consistency = ON
+bind-address = "0.0.0.0"
+server_id = ${svr_id}
+EOL
+
+export pid
+
+function start_mysqld_in_background() {
+    log "INFO" "Starting mysql server with 'docker-entrypoint.sh mysqld $args'..."
+    docker-entrypoint.sh mysqld $args &
+    pid=$!
+    log "INFO" "The process id of mysqld is '$pid'"
+}
+
+function install_clone_plugin() {
+    log "INFO" "Checking whether clone plugin on host $1 is installed or not...."
+    local mysql="$mysql_header --host=$1"
+
+    # At first, ensure that the command executes without any error. Then, run the command again and extract the output.
+    retry 120 ${mysql} -N -e 'SHOW PLUGINS;' | grep clone
+    out=$(${mysql} -N -e 'SHOW PLUGINS;' | grep clone)
+    if [[ -z "$out" ]]; then
+        log "INFO" "Clone plugin is not installed. Installing the plugin..."
+        retry 120 ${mysql} -e "INSTALL PLUGIN clone SONAME 'mysql_clone.so';"
+        reading_first_time=1
+        retry 120 ${mysql} -e "reset master;"
+        log "INFO" "Clone plugin successfully installed"
+    else
+        log "INFO" "Already clone plugin is installed"
+    fi
+}
+
+function install_semiSync_plugin() {
+    log "INFO" "Checking whether semi_sync plugin on host $1 is installed or not...."
+    local mysql="$mysql_header --host=$1"
+
+    # At first, ensure that the command executes without any error. Then, run the command again and extract the output.
+    retry 120 ${mysql} -N -e 'SHOW PLUGINS;' | grep semisync
+    out=$(${mysql} -N -e 'SHOW PLUGINS;' | grep semisync)
+    if [[ -z "$out" ]]; then
+        log "INFO" "semisync plugin is not installed. Installing the plugin..."
+        retry 120 ${mysql} -e "INSTALL PLUGIN rpl_semi_sync_master SONAME 'semisync_master.so';"
+        retry 120 ${mysql} -e "INSTALL PLUGIN rpl_semi_sync_slave SONAME 'semisync_slave.so';"
+        reading_first_time=1
+        log "INFO" "semi_sync plugin successfully installed"
+    else
+        log "INFO" "Already semi_sync plugin is installed"
+    fi
+}
+
+# wait for mysql daemon be running (alive)
+function wait_for_mysqld_running() {
+    local mysql="$mysql_header --host=$localhost"
+
+    for i in {900..0}; do
+        out=$(mysql -N -e "select 1;" 2>/dev/null)
+        log "INFO" "Attempt $i: Pinging '$report_host' has returned: '$out'...................................."
+        if [[ "$out" == "1" ]]; then
+            break
+        fi
+
+        echo -n .
+        sleep 1
+    done
+
+    if [[ "$i" == "0" ]]; then
+        echo ""
+        log "ERROR" "Server ${report_host} failed to start in 900 seconds............."
+        exit 1
+    fi
+    log "INFO" "mysql daemon is ready to use......."
+}
+
+# create mysql client with user exported in mysql_header and export password
+# this is to bypass the warning message for using password
+
+start_mysqld_in_background
+
+export mysql_header="mysql -u ${USER} --port=3306"
+export MYSQL_PWD=${PASSWORD}
+
+wait_for_mysqld_running
+
+install_clone_plugin "localhost"
+
+install_semiSync_plugin "localhost"
+
+while true; do
+    kill -0 $pid
+    exit="$?"
+    if [[ "$exit" == "0" ]]; then
+        echo "mysqld process is running"
+    else
+        echo "need to start mysqld and wait_for_mysqld_running"
+        start_mysqld_in_background
+        wait_for_mysqld_running
+    fi
+    log "INFO" "waiting for mysql process $pid."
+    wait $pid
+done