Tune MariaDB config generation

This commit is contained in:
Marek Miklewicz
2026-06-13 20:49:00 +02:00
parent d0ac04f38b
commit db01ba1ea0
4 changed files with 356 additions and 55 deletions
Executable
+274
View File
@@ -0,0 +1,274 @@
#!/usr/bin/env bash
set -euo pipefail
MARIADB_MEMORY_PERCENT=25
MIN_BUFFER_POOL_MB=256
MAX_CONNECTIONS_MIN=80
MAX_CONNECTIONS_MAX=300
usage() {
cat <<'EOF'
Usage:
my-cnf-gen.sh [--output PATH]
Generates a conservative MariaDB 10.6 my.cnf for DirectAdmin servers.
The InnoDB buffer pool is sized to about 25% RAM so other DA services
such as web, exim, dovecot, redis and spam filtering keep enough memory.
EOF
}
read_mem_total_mb() {
local mem_bytes
if [[ -n "${MYSQL_GEN_MEM_MB:-}" ]]; then
printf '%s\n' "$MYSQL_GEN_MEM_MB"
return 0
fi
if [[ -r /proc/meminfo ]]; then
awk '/^MemTotal:/ { printf "%d\n", int($2 / 1024) }' /proc/meminfo
return 0
fi
mem_bytes="$(sysctl -n hw.memsize 2>/dev/null || true)"
if [[ -n "$mem_bytes" ]]; then
printf '%d\n' "$((mem_bytes / 1024 / 1024))"
return 0
fi
echo "Unable to detect total memory" >&2
exit 1
}
read_cpu_cores() {
local cores
cores=""
if [[ -n "${MYSQL_GEN_CPU_CORES:-}" ]]; then
printf '%s\n' "$MYSQL_GEN_CPU_CORES"
return 0
fi
if [[ -r /proc/cpuinfo ]]; then
cores="$(grep -c '^processor[[:space:]]*:' /proc/cpuinfo 2>/dev/null || true)"
fi
if [[ -z "$cores" || "$cores" -lt 1 ]]; then
cores="$(getconf _NPROCESSORS_ONLN 2>/dev/null || true)"
fi
if [[ -z "$cores" || "$cores" -lt 1 ]]; then
cores=1
fi
printf '%s\n' "$cores"
}
round_down_mb() {
local value_mb="$1"
local step_mb="$2"
local rounded
rounded=$((value_mb / step_mb * step_mb))
if (( rounded < step_mb )); then
rounded="$step_mb"
fi
printf '%s\n' "$rounded"
}
format_size() {
local value_mb="$1"
if (( value_mb >= 1024 && value_mb % 1024 == 0 )); then
printf '%sG\n' "$((value_mb / 1024))"
else
printf '%sM\n' "$value_mb"
fi
}
calc_buffer_pool_mb() {
local mem_mb="$1"
local pool_mb
pool_mb=$((mem_mb * MARIADB_MEMORY_PERCENT / 100))
if (( pool_mb < MIN_BUFFER_POOL_MB )); then
pool_mb="$MIN_BUFFER_POOL_MB"
fi
round_down_mb "$pool_mb" 128
}
calc_buffer_pool_instances() {
local pool_mb="$1"
local cores="$2"
local instances=1
if (( pool_mb >= 8192 && cores >= 4 )); then
instances=4
elif (( pool_mb >= 4096 && cores >= 2 )); then
instances=2
fi
printf '%s\n' "$instances"
}
calc_max_connections() {
local mem_mb="$1"
local cores="$2"
local connections
connections=$((mem_mb / 128))
if (( connections < MAX_CONNECTIONS_MIN )); then
connections="$MAX_CONNECTIONS_MIN"
fi
if (( connections > MAX_CONNECTIONS_MAX )); then
connections="$MAX_CONNECTIONS_MAX"
fi
if (( cores <= 2 && connections > 120 )); then
connections=120
fi
printf '%s\n' "$connections"
}
calc_log_file_mb() {
local pool_mb="$1"
local log_mb
log_mb=$((pool_mb / 4))
if (( log_mb < 128 )); then
log_mb=128
elif (( log_mb > 1024 )); then
log_mb=1024
fi
round_down_mb "$log_mb" 128
}
generate_config() {
local mem_mb="$1"
local cores="$2"
local pool_mb="$3"
local pool_instances="$4"
local max_connections="$5"
local log_file_mb="$6"
local io_capacity="$7"
local io_capacity_max="$8"
cat <<EOF
# Generated by my-cnf-gen.sh for MariaDB 10.6 and DirectAdmin stack hosts.
# Detected RAM: ${mem_mb}M
# Detected CPU cores: ${cores}
# MariaDB memory budget: ${MARIADB_MEMORY_PERCENT}% RAM
[client]
port=3306
socket=/var/lib/mysql/mysql.sock
default-character-set=utf8mb4
[mysql]
default-character-set=utf8mb4
[mysqld]
user=mysql
port=3306
socket=/var/lib/mysql/mysql.sock
pid-file=/var/lib/mysql/mysql.pid
datadir=/var/lib/mysql
local_infile=0
skip_name_resolve=1
symbolic_links=0
max_connect_errors=1000000
max_allowed_packet=64M
character-set-server=utf8mb4
collation-server=utf8mb4_unicode_ci
skip-character-set-client-handshake
default_storage_engine=InnoDB
myisam_recover_options=FORCE,BACKUP
key_buffer_size=32M
max_connections=${max_connections}
max_user_connections=50
thread_cache_size=64
table_open_cache=2048
table_definition_cache=1024
open_files_limit=65535
sort_buffer_size=512K
join_buffer_size=512K
read_buffer_size=256K
read_rnd_buffer_size=512K
tmp_table_size=32M
max_heap_table_size=32M
query_cache_type=0
query_cache_size=0
innodb_buffer_pool_size=$(format_size "$pool_mb")
innodb_buffer_pool_instances=${pool_instances}
innodb_log_file_size=$(format_size "$log_file_mb")
innodb_log_files_in_group=2
innodb_flush_log_at_trx_commit=1
innodb_flush_method=O_DIRECT
innodb_file_per_table=1
innodb_io_capacity=${io_capacity}
innodb_io_capacity_max=${io_capacity_max}
log_error=/var/lib/mysql/mysql-error.log
slow_query_log=0
slow_query_log_file=/var/lib/mysql/mysql-slow.log
long_query_time=2
log_queries_not_using_indexes=0
EOF
}
main() {
local output=""
local mem_mb
local cores
local pool_mb
local pool_instances
local max_connections
local log_file_mb
local io_capacity
local io_capacity_max
while [[ $# -gt 0 ]]; do
case "$1" in
--output)
shift
[[ $# -gt 0 ]] || { echo "Missing value for --output" >&2; exit 1; }
output="$1"
;;
--help|-h)
usage
exit 0
;;
*)
echo "Unknown argument: $1" >&2
usage >&2
exit 1
;;
esac
shift
done
mem_mb="$(read_mem_total_mb)"
cores="$(read_cpu_cores)"
pool_mb="$(calc_buffer_pool_mb "$mem_mb")"
pool_instances="$(calc_buffer_pool_instances "$pool_mb" "$cores")"
max_connections="$(calc_max_connections "$mem_mb" "$cores")"
log_file_mb="$(calc_log_file_mb "$pool_mb")"
io_capacity=$((cores * 100))
if (( io_capacity < 200 )); then
io_capacity=200
elif (( io_capacity > 800 )); then
io_capacity=800
fi
io_capacity_max=$((io_capacity * 2))
if [[ -n "$output" ]]; then
generate_config "$mem_mb" "$cores" "$pool_mb" "$pool_instances" "$max_connections" "$log_file_mb" "$io_capacity" "$io_capacity_max" > "$output"
else
generate_config "$mem_mb" "$cores" "$pool_mb" "$pool_instances" "$max_connections" "$log_file_mb" "$io_capacity" "$io_capacity_max"
fi
}
main "$@"