swift-ops-storage-node-drop-slab-cache

#!bin/bash -u

# upgrade swift packages
sudo apt update
sudo apt install swift --only-upgrade

# increase this from default of 100 to allow kernel to release xfs cache data more readily
sudo sysctl -w vm.vfs_cache_pressure=200

# make a note of the following
free -lh
egrep "Slab|Reclaim" /proc/meminfo

manage ()
{
    action=$1
    filter=${2:-""}
    declare -a svcs=(
    swift-account-auditor
    swift-account-reaper
    swift-account-replicator
    swift-account
    swift-container-auditor
    swift-container-replicator
    swift-container-sync
    swift-container-updater
    swift-container
    swift-object-auditor
    swift-object-replicator
    swift-object-updater
    swift-object
    )
    set -x
    for svc in ${svcs[@]}; do
        [ -z "$filter" ] || `echo $svc| grep -q $filter` || continue
        sudo service $svc $action
    done
    set +x

    # show what's running
    [ -z "$filter" ] && \
        pgrep -alf /swift| awk '{print $3}'| sort| uniq || \
            pgrep -alf /swift| awk '{print $3}'| sort| uniq| grep $filter
}

# Stop the services
manage stop

# It might be necessary to manually kill -9 a remaining swift-object-replicator process

# repeat the following at least once (or until SReclaimable in /proc/meminfo is at an acceptable level)
sync
echo 2| sudo tee /proc/sys/vm/drop_caches
echo 1| sudo tee /proc/sys/vm/compact_memory

# make a note of the following
free -lh
egrep "Slab|Reclaim" /proc/meminfo

# Start services
manage start