PATH=/usr/bin:/bin
DIR=”/var/backup/mysql”
KEEP=”7″

datecomp=`date -d “$KEEP days ago” +%Y%m%d`
ts=`date +%Y%m%d`
dbs=`mysql -u root -p’xxx’ -ABNe ‘show databases’`
function purge() {
prefix=$1
for filename in `ls | grep “^$prefix-”`; do
        idate=`echo $filename | sed “s/^$prefix-\([0-9]*\).sql$/\1/”`
        if [ $idate -le $datecomp ]; then
                rm $filename
        fi
done
}

pushd $DIR > /dev/null

for db in $dbs
do
 mysqldump –opt –quote-names -u root -p’xxx’ $db > $DIR/$db-$ts.sql
 purge $db 
done

popd > /dev/null

http://www.danga.com/memcached/

http://repcached.lab.klab.org/

Memcached and facebook: http://edwink.devhd.com/2008/01/05/mysql-memcached-and-replication/

PHP client http://pecl.php.net/package/memcache

memcache 3.x should support ini option:

memcache.redundancy = 1
memcache.session_redundancy = 2

http://code.google.com/p/webgrind/