Quickstart

Start fastcached and round-trip a value with the client that ships beside it.

1. Run the daemon

./fastcached

It listens on 127.0.0.1:6674 — fastcached's own port. The number selects no protocol: everything below reaches the same daemon on the same port, because the wire format is detected per connection.

2. Store and fetch a value

fastcache-cli is the first-party client — see fastcache-cli for the full reference:

$ fastcache-cli set greeting hello --ttl 60s
$ fastcache-cli get greeting
hello
$ fastcache-cli ttl greeting
key     greeting
exists  true
ttl     59
$ fastcache-cli del greeting
1

A verb that only succeeds or fails prints nothing and says so through its exit status; one that answers a question prints the answer, and one that answers several prints a two-column record.

A miss exits 1, a daemon that cannot be reached exits 3, and a usage mistake exits 2 — so a shell script can tell those three apart:

$ fastcache-cli get nothing-here; echo "exit=$?"
exit=1

3. Ask it for stats

Human-readable by default, machine-readable on request:

$ fastcache-cli stats
source                    info
fastcached_version        fastcached-0.2.0
used_memory               94
maxmemory                 8589934592
total_commands_processed  6
...
$ fastcache-cli stats --format=json
{"source":"info","fastcached_version":"fastcached-0.2.0","used_memory":94,...}
$ fastcache-cli stats --format=tsv

The first field is the source, because the sources differ enormously in richness and a number means little without knowing which answered. RESP INFO carries 8 fields; the daemon's /metrics endpoint carries over a hundred. Start the daemon with --metrics and the same command reports source metrics and far more of them.

4. Speak the protocols by hand

The wire formats are still plain text, which is useful when you are debugging the protocols themselves rather than the cache.

The ASCII text protocol over telnet:

$ telnet 127.0.0.1 6674
> set greeting 0 60 5
> hello
< STORED
> get greeting
< VALUE greeting 0 5
< hello
< END
> quit

The same connection accepts the modern meta commands:

> mg greeting v
< VA 5
< hello
> ms counter 1 T60
> 0
< HD
> ma counter v
< VA 1
< 1

And the Redis handler answers redis-cli on the same port:

$ redis-cli -p 6674
127.0.0.1:6674> SET greeting hello EX 60
OK
127.0.0.1:6674> GET greeting
"hello"

See Protocols overview for the auto-detection rules, and Redis RESP for which Redis commands are answered.