From d5af514ac9485009229f3b594bccc09e905782fb Mon Sep 17 00:00:00 2001 From: Gorka Eguileor Date: Wed, 8 Jun 2022 10:19:50 +0200 Subject: [PATCH] Reduce memory consumption in Cinder services This patch reduces memory usage on the Cinder Volume and Backup services by tuning glibc. The specific tuning consist on disabling the per thread arenas and disabling dynamic thresholds. The Cinder Backup service suffers from high water mark memory usage and uses excessive memory. As an example just after 10 restore operations the service uses almost 1GB of RAM and does not ever free it afterwards. With this patch the memory consumption of the service is reduced down to almost 130MB. If we add a revert from Cinder (Change-Id I43a20c8687f12bc52b014611cc6977c4c3ca212c) it goes down to 100MB during my tests. This glibc tuning is not applied to all Python services because I haven't done proper testings on them and at first glance they don't seem to have such great improvements. Related-bug: #1908805 Change-Id: Ic9030d01468b3189350f83b04a8d1d346c489d3c --- functions-common | 22 ++++++++++++++++++---- lib/cinder | 9 +++++++-- 2 files changed, 25 insertions(+), 6 deletions(-) diff --git a/functions-common b/functions-common index be966e96a6..0b896dde59 100644 --- a/functions-common +++ b/functions-common @@ -1564,6 +1564,7 @@ function write_user_unit_file { local command="$2" local group=$3 local user=$4 + local env_vars="$5" local extra="" if [[ -n "$group" ]]; then extra="Group=$group" @@ -1577,6 +1578,9 @@ function write_user_unit_file { iniset -sudo $unitfile "Service" "KillMode" "process" iniset -sudo $unitfile "Service" "TimeoutStopSec" "300" iniset -sudo $unitfile "Service" "ExecReload" "$KILL_PATH -HUP \$MAINPID" + if [[ -n "$env_vars" ]] ; then + iniset -sudo $unitfile "Service" "Environment" "$env_vars" + fi if [[ -n "$group" ]]; then iniset -sudo $unitfile "Service" "Group" "$group" fi @@ -1591,6 +1595,7 @@ function write_uwsgi_user_unit_file { local command="$2" local group=$3 local user=$4 + local env_vars="$5" local unitfile="$SYSTEMD_DIR/$service" mkdir -p $SYSTEMD_DIR @@ -1605,6 +1610,9 @@ function write_uwsgi_user_unit_file { iniset -sudo $unitfile "Service" "NotifyAccess" "all" iniset -sudo $unitfile "Service" "RestartForceExitStatus" "100" + if [[ -n "$env_vars" ]] ; then + iniset -sudo $unitfile "Service" "Environment" "$env_vars" + fi if [[ -n "$group" ]]; then iniset -sudo $unitfile "Service" "Group" "$group" fi @@ -1652,10 +1660,14 @@ function _run_under_systemd { local systemd_service="devstack@$service.service" local group=$3 local user=${4:-$STACK_USER} + if [[ -z "$user" ]]; then + user=$STACK_USER + fi + local env_vars="$5" if [[ "$command" =~ "uwsgi" ]] ; then - write_uwsgi_user_unit_file $systemd_service "$cmd" "$group" "$user" + write_uwsgi_user_unit_file $systemd_service "$cmd" "$group" "$user" "$env_vars" else - write_user_unit_file $systemd_service "$cmd" "$group" "$user" + write_user_unit_file $systemd_service "$cmd" "$group" "$user" "$env_vars" fi $SYSTEMCTL enable $systemd_service @@ -1676,18 +1688,20 @@ function is_running { # If the command includes shell metachatacters (;<>*) it must be run using a shell # If an optional group is provided sg will be used to run the # command as that group. -# run_process service "command-line" [group] [user] +# run_process service "command-line" [group] [user] [env_vars] +# env_vars must be a space separated list of variable assigments, ie: "A=1 B=2" function run_process { local service=$1 local command="$2" local group=$3 local user=$4 + local env_vars="$5" local name=$service time_start "run_process" if is_service_enabled $service; then - _run_under_systemd "$name" "$command" "$group" "$user" + _run_under_systemd "$name" "$command" "$group" "$user" "$env_vars" fi time_stop "run_process" } diff --git a/lib/cinder b/lib/cinder index 52818a81eb..ca2c084aff 100644 --- a/lib/cinder +++ b/lib/cinder @@ -552,8 +552,13 @@ function start_cinder { fi run_process c-sch "$CINDER_BIN_DIR/cinder-scheduler --config-file $CINDER_CONF" - run_process c-bak "$CINDER_BIN_DIR/cinder-backup --config-file $CINDER_CONF" - run_process c-vol "$CINDER_BIN_DIR/cinder-volume --config-file $CINDER_CONF" + # Tune glibc for Python Services using single malloc arena for all threads + # and disabling dynamic thresholds to reduce memory usage when using native + # threads directly or via eventlet.tpool + # https://www.gnu.org/software/libc/manual/html_node/Memory-Allocation-Tunables.html + malloc_tuning="MALLOC_ARENA_MAX=1 MALLOC_MMAP_THRESHOLD_=131072 MALLOC_TRIM_THRESHOLD_=262144" + run_process c-bak "$CINDER_BIN_DIR/cinder-backup --config-file $CINDER_CONF" "" "" "$malloc_tuning" + run_process c-vol "$CINDER_BIN_DIR/cinder-volume --config-file $CINDER_CONF" "" "" "$malloc_tuning" # NOTE(jdg): For cinder, startup order matters. To ensure that repor_capabilities is received # by the scheduler start the cinder-volume service last (or restart it) after the scheduler