memcachedb - Online in the Cloud

PROGRAM:

NAME

memcachedb - persistence-enabled variant of memcached

SYNOPSIS

memcachedb [OPTIONS]

DESCRIPTION

MemcacheDB (pronounced mem-cash-dee-bee) is a persistence-enabled variant of the memcached
distributed key-value storage system. It is NOT a cache solution, but rather a persistent
storage engine for fast and reliable key-value based object storage and retrieval.

It conforms to the memcache protocol, which means that memcached clients can connect and
use the persistent key-value store transparently. It also provides reliability and high-
availability through its transaction and replication support, courtesy of its BerkeleyDB
storage backend.

OPTIONS

-p <num>
TCP port to listen on (default: 21201)

-U <num>
UDP port to listen on (default: 0, off)

-s <file>
UNIX Domain Socket path to listen on (disables network support)

-a <mask>
Access mask for unix socket, in octal (default: 0700)

-l <ip_addr>
Interface to listen on (default: INADRR_ANY)

-d Run as a daemon

-r Maximize core file limit

-u <username>
Assume identity of <username> (only when run as root)

-c <num>
Maximum simultaneous connections (default: 4096)

-b <num>
Item size smaller than <num> bytes will use fast memory allocation (default: 2048
bytes)

-v Verbose (print errors/warnings while in event loop)

-vv Very verbose (also print client commands/reponses)

-h Print brief usage instructions and exit

-i Print complete copyright and license information

-P <file>
Save process ID in <file> (only used with the -d option)

-t <num>
Number of threads to use (default: 4)

Berkeley DB Options
-m <num>
In-memory cache size of BerkeleyDB in megabytes (default: 256MB)

-A <num>
Underlying page size in bytes (default: 4096, range: 512B-64KB, power-of-two)

-f <file>
Filename of database (default: data.db)

-H <dir>
Environment HOME of database (default: /data1/memcachedb)

-G <dir>
Log directory of database (default: same as Environment HOME, see -H)

-B <db_type>
Type of database, options are: 'btree' or 'hash' (default: btree)

-L <num>
Log buffer size in kBytes (default: 4096kB)

-C <num>
Perform a checkpoint every <num> seconds (0 to disable, default: 300 seconds)

-T <num>
Do memp_trickle every <num> seconds (0 to disable, default: 30 seconds)

-e <num>
Percentage of the pages in the cache that should be clean (default: 60%)

-D <num>
Perform deadlock detection every <num> milliseconds (0 to disable, default: 100ms)

-N Enable DB_TXN_NOSYNC for a large performance gain (default: off)

-E Automatically remove log files that are no longer needed

-X Allocate region memory from the heap (default: off)

Replication Options
-R Identifies the host and port used by this site (required)

-O Identifies another site participating in this replication group

-M/-S Start memcachedb as a master or slave

-n <num>
Number of sites participating in replication (default: 2)

CAVEATS

· Because this is a persistent storage solution, expire time specified in the
corresponding memcache protocol clients will be silently discarded.

Use memcachedb online using onworks.net services