b52

b52 is a fast experimental Key/value database. With support for the memcache protocol.

Getting Started

Installing

To start using b52, install Go and run go get:

$ go get -u github.com/recoilme/b52
$ go build or go install

This will retrieve and build the server. Or grab compiled binary version.

Starting

Use ./b52 --help for full list of params. Example:

./b52 -p 11212 -params "sizelru=10&sizettl=10&dbdir="
# Start server on port 11212 with 10Mb lru and ttl cache size, without persistent database.

or just ./b52 - for start with default params

How it work

b52 is a layered database composed of a sniper, evio and freecache. When b52 prepared properly, the ingredients separate into three distinctly visible layers.

It use evio for network communications.

sniper - fast, persistant on disk storage

freecache - in memory, with zero GC overhead cache, for keys with TTL (time to live) and LRU cache

The balance between speed and efficiency is achieved as follows:

New entries go to disk (sniper). As you access them, they are cached in the LRU-cache (freecache). Life-limited records are stored separately, in freecache (without persistance storage).

Memory usage

For minimizing GC and allocations overhead - Sniper stored keys, and value addres/size in plain hash (map[uint32]uint32). HashMaps are fast, but has a memory cost. You must have 2Gb+ memory for storing every 100_000_000 entrys.

In Freecache memory is preallocated and it's size depends from you.

Disk usage

Sniper has a minimum 8 byte overhead on every entry. But it allocate space in power of 2, and try to reuse space, if value grow. Also, sniper will try to reuse space from deleted/evicted records.

Telnet example

telnet localhost 11211
set a 0 0 5
12345
STORED
get a
VALUE a 0 5
12345
END
close

Memcache protocol

b52 use text version of memcache protocol. With this commands:

	cmdAdd       = []byte("add")
	cmdReplace   = []byte("replace")
	cmdSet       = []byte("set")
	cmdGet       = []byte("get")
	cmdGets      = []byte("gets")
	cmdClose     = []byte("close")
	cmdDelete    = []byte("delete")
	cmdIncr      = []byte("incr")
	cmdDecr      = []byte("decr")
	cmdStats     = []byte("stats")
	cmdQuit      = []byte("quit")
	cmdVersion   = []byte("version")

mc-benchmark

mc-benchmark

Database params (running as master/slave, 1Gb lru cache, 100 Mb ttl cache, stats after 3 days using):
stats
STAT version 0.1.3
bytes 2301825272
heap_sys_mb 2103
curr_items 17165174
cmd_get 6660544669
cmd_set 6494641380
file_size 14172392544

test (on production, with ~2k active connections at same time):
./mc-benchmark -p 11222

====== SET ======
  10000 requests completed in 0.10 seconds
  50 parallel clients
  3 bytes payload
  keep alive: 1

56.39% <= 0 milliseconds
95.39% <= 1 milliseconds
100.00% <= 2 milliseconds
101010.10 requests per second

====== GET ======
  10014 requests completed in 0.08 seconds
  50 parallel clients
  3 bytes payload
  keep alive: 1

60.25% <= 0 milliseconds
100.00% <= 1 milliseconds
123629.63 requests per second

./mc-benchmark -n 100000 -p 11212
====== SET ======
  100003 requests completed in 1.03 seconds
  50 parallel clients
  3 bytes payload
  keep alive: 1

49.59% <= 0 milliseconds
99.16% <= 1 milliseconds
100.00% <= 2 milliseconds
96996.12 requests per second

====== GET ======
  100018 requests completed in 0.98 seconds
  50 parallel clients
  3 bytes payload
  keep alive: 1

51.55% <= 0 milliseconds
99.72% <= 1 milliseconds
99.99% <= 2 milliseconds
100.00% <= 3 milliseconds
101851.33 requests per second

expvar

Contact

Vadim Kulibaba @recoilme

License

b52 source code is available under the MIT License.