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| 1 | +#!/usr/bin/env bash |
| 2 | + |
| 3 | +set -eu |
| 4 | +set -o pipefail |
| 5 | + |
| 6 | +BACKUP_DIR=/backup/ |
| 7 | +DEFAULT_MY_CNF="/etc/mysql/my.cnf" |
| 8 | +REPLICA_MY_CNF="$(mktemp)" |
| 9 | +RETRY_INTERVAL=5 # Interval between retries (in seconds) |
| 10 | +MAX_RETRIES=12 # Max retries (12 retries * 5 seconds = 60 seconds) |
| 11 | + |
| 12 | +# Cleanup function to remove the REPLICA_MY_CNF file |
| 13 | +cleanup() { |
| 14 | + rm -f "${REPLICA_MY_CNF}" |
| 15 | +} |
| 16 | + |
| 17 | +# Set trap to ensure cleanup occurs on exit or error |
| 18 | +trap cleanup EXIT |
| 19 | + |
| 20 | +cd "${BACKUP_DIR}" |
| 21 | + |
| 22 | +# Execute a full backup |
| 23 | +backup_full() { |
| 24 | + echo "Taking a full backup" |
| 25 | + LAST_FULL_DATE=$(date +%d-%m-%Y-%s) |
| 26 | + mariabackup \ |
| 27 | + --defaults-file="${REPLICA_MY_CNF}" \ |
| 28 | + --backup \ |
| 29 | + --stream=mbstream \ |
| 30 | + --history="${LAST_FULL_DATE}" | gzip > \ |
| 31 | + "${BACKUP_DIR}/mysqlbackup-${LAST_FULL_DATE}.qp.mbc.mbs.gz" && \ |
| 32 | + echo "${LAST_FULL_DATE}" > "${BACKUP_DIR}/last_full_date" |
| 33 | +} |
| 34 | + |
| 35 | +# Execute an incremental backup |
| 36 | +backup_incremental() { |
| 37 | + if [ -r "${BACKUP_DIR}/last_full_date" ]; then |
| 38 | + LAST_FULL_DATE=$(cat "${BACKUP_DIR}/last_full_date") |
| 39 | + else |
| 40 | + LAST_FULL_DATE="" |
| 41 | + fi |
| 42 | + if [ ! -z "${LAST_FULL_DATE}" ]; then |
| 43 | + echo "Taking an incremental backup" |
| 44 | + mariabackup \ |
| 45 | + --defaults-file="${REPLICA_MY_CNF}" \ |
| 46 | + --backup \ |
| 47 | + --stream=mbstream \ |
| 48 | + --incremental-history-name="${LAST_FULL_DATE}" \ |
| 49 | + --history="${LAST_FULL_DATE}" | gzip > \ |
| 50 | + "${BACKUP_DIR}/incremental-$(date +%H)-mysqlbackup-${LAST_FULL_DATE}.qp.mbc.mbs.gz" |
| 51 | + else |
| 52 | + echo "Error: Full backup don't exist." |
| 53 | + exit 1 |
| 54 | + fi |
| 55 | +} |
| 56 | + |
| 57 | +# Retry logic for database queries |
| 58 | +retry_mysql_query() { |
| 59 | + local query="$1" |
| 60 | + local result="" |
| 61 | + local attempt=1 |
| 62 | + |
| 63 | + while [ ${attempt} -le ${MAX_RETRIES} ]; do |
| 64 | + result=$(mysql -h "${HOST}" -u "${USER}" -p"${PASS}" -s -N -e "${query}" 2>/dev/null || true) |
| 65 | + if [ -n "${result}" ]; then |
| 66 | + echo "${result}" |
| 67 | + return 0 |
| 68 | + fi |
| 69 | + echo "Attempt ${attempt}/${MAX_RETRIES} failed. Retrying in ${RETRY_INTERVAL} seconds..." |
| 70 | + sleep "${RETRY_INTERVAL}" |
| 71 | + attempt=$((attempt + 1)) |
| 72 | + done |
| 73 | + |
| 74 | + echo "Error: Failed to execute the query after ${MAX_RETRIES} attempts." |
| 75 | + return 1 |
| 76 | +} |
| 77 | + |
| 78 | +get_and_set_replica_server() { |
| 79 | + HOST="$(grep '^host' "${DEFAULT_MY_CNF}" | awk -F '=' '{print $2}' | xargs)" |
| 80 | + USER="$(grep '^user' "${DEFAULT_MY_CNF}" | awk -F '=' '{print $2}' | xargs)" |
| 81 | + PASS="$(grep '^password' "${DEFAULT_MY_CNF}" | awk -F '=' '{print $2}' | xargs)" |
| 82 | + |
| 83 | + ALL_HOSTS_SELECT="SELECT REGEXP_REPLACE(VARIABLE_VALUE, ':[0-9]*','') FROM information_schema.GLOBAL_STATUS WHERE VARIABLE_NAME = 'wsrep_incoming_addresses';" |
| 84 | + ALL_HOSTS=$(retry_mysql_query "${ALL_HOSTS_SELECT}") |
| 85 | + if [ -z "${ALL_HOSTS}" ]; then |
| 86 | + echo "Backup failed due to inability to fetch a list of servers." |
| 87 | + exit 1 |
| 88 | + fi |
| 89 | + |
| 90 | + ACTIVE_HOST_SELECT='SELECT @@hostname;' |
| 91 | + ACTIVE_HOST=$(retry_mysql_query "${ACTIVE_HOST_SELECT}" | xargs getent hosts | awk '{print $1}') |
| 92 | + if [ -z "${ACTIVE_HOST}" ]; then |
| 93 | + echo "Backup failed due to inability to fetch active host." |
| 94 | + exit 1 |
| 95 | + fi |
| 96 | + |
| 97 | + # Multinode |
| 98 | + if echo "${ALL_HOSTS}" | grep -q ','; then |
| 99 | + for server in $(echo "${ALL_HOSTS}" | tr ',' '\n'); do |
| 100 | + if [[ "${server}" != "${ACTIVE_HOST}" ]]; then |
| 101 | + REPLICA_HOST="${server}" |
| 102 | + break |
| 103 | + fi |
| 104 | + done |
| 105 | + # Single node |
| 106 | + else |
| 107 | + REPLICA_HOST="${ALL_HOSTS}" |
| 108 | + fi |
| 109 | + if [ -z "${REPLICA_HOST}" ]; then |
| 110 | + echo "Backup failed due to inability to determine replica host." |
| 111 | + exit 1 |
| 112 | + fi |
| 113 | + |
| 114 | + cp "${DEFAULT_MY_CNF}" "${REPLICA_MY_CNF}" |
| 115 | + sed -i "s/${HOST}/${REPLICA_HOST}/g" "${REPLICA_MY_CNF}" |
| 116 | +} |
| 117 | + |
| 118 | +if [ -n "${BACKUP_TYPE}" ]; then |
| 119 | + get_and_set_replica_server |
| 120 | + case "${BACKUP_TYPE}" in |
| 121 | + "full") |
| 122 | + backup_full |
| 123 | + ;; |
| 124 | + "incremental") |
| 125 | + backup_incremental |
| 126 | + ;; |
| 127 | + *) |
| 128 | + echo "Only full or incremental options are supported." |
| 129 | + exit 1 |
| 130 | + ;; |
| 131 | + esac |
| 132 | +else |
| 133 | + echo "You need to specify either full or incremental backup options." |
| 134 | + exit 1 |
| 135 | +fi |
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