C implementation of a full-featured shardcache daemon
shardcached implements an http frontend exposing all functionalities provided by libshardcache.
- the internal counters and the storage index are exposed through the 'magic' keys (urls) :
__index__and__stats__. - allows to define ACLs to control which IP addresses can access which keys (including the internal keys
__index__and__stats__) - supports mime-types rules to use when serving back items via the http frontend
- pluggable storage backend (sqlite, mysql and redis storage plugins have been already implemented and provided as examples in the
storage_plugins/directory) - provides builtin storage modules for both volatile (mem-based) and persistent (filesystem-based) storage
- supports migrations which can be initiated by new nodes at their startup
NOTE: Almost all options can be controlled/overridden via the cmdline, ACLs and mime-types rules are supported only via the configuration file.
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Usage: ./shardcached [OPTION]...
Version: 0.17 (libshardcache: 0.22)
Possible options:
-a <access_log_file> the path where to store the access_log file (defaults to './shardcached_access.log')
-c <config_file> the config file to load
-d <plugins_path> the path where to look for storage plugins (defaults to './')
-f run in foreground
-F force caching
-H disable the HTTP frontend
-i <interval> change the time interval (in seconds) used to report internal stats via syslog (defaults to '0')
-l <ip_address:port> ip_address:port where to listen for incoming http connections
-L enable lazy expiration
-E <expire_time> set the expiration time for cached items (defaults to: 0)
-e <conn_expire_time> the expiration time for a connection in the pool to trigger a NOOP (defaults to 30000)
-r <mux_timeout_low> set the low timeout passed to iomux_run() calls (in microsecs, defaults to: 100000)
-R <mux_timeout_high> set the high timeout pssed to iomux_run() calls (in microsecs, defaults to: 500000)
-b HTTP url basepath (optional, defaults to '')
-B HTTP url baseadminpath (optional, defaults to '')
-n <nodes> list of nodes participating in the shardcache in the form : 'label:address:port,label2:address2:port2'
-N no storage subsystem, use only the internal libshardcache volatile storage
-m me the label of this node, to identify it among the ones participating in the shardcache
-P <pipelining_max> the maximum amount of requests to handle in parallel while still serving a response (defaults to: 64)
-S shared secret used for message signing (defaults to : '')
-s cache size in bytes (defaults to : '536870912')
-T <tcp_timeout> tcp timeout (in milliseconds) used for connections opened by libshardcache (defaults to '5000')
-t <type> storage type (available are : 'mem' and 'fs' (defaults to 'mem')
-o <options> comma-separated list of storage options (defaults to '')
-u <username> assume the identity of <username> (only when run as root)
-v increase the log level (can be passed multiple times)
-V output the version number and exit
-w <num_workers> number of shardcache worker threads (defaults to '10')
-W <num_http_workers> number of http worker threads (defaults to '10')
-x <nodes> new list of nodes to migrate the shardcache to. The format to use is the same as for the '-n' option
Builtin storage types:
* mem memory based storage
Options:
- initial_table_size=<size> the initial number of slots in the internal hashtable
- max_table_size=<size> the maximum number of slots that the internal hashtable can be grown up to
* fs filesystem based storage
Options:
- storage_path=<path> the path where to store the keys/values on the filesystem
- tmp_path=<path> the path to a temporary directory to use while new data is being uploaded
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Example configuration file :
[shardcached]
stats_interval = 0 ; The interval in seconds at which output stats to stdout and/or syslog
; if '0' no stats will be reported on stdout/systlog
; (optional, defaults to '0')
storage_type = fs ; The storage type (optional, defaults to 'mem')
storage_options = storage_path=/home/xant/shardcache_storage,tmp_path=/tmp
; storage options (possibly optional, depend on the storage implementation)
plugins_dir = ./ ; The directory where to find plugins (optional, defaults to './')
loglevel = 2 ; The loglevel (optional, defaults to '0' == upto(LOG_ERR))
daemon = no ; Run as daemon or in foreground (optional, defaults to 'yes')
nohttp = no ; Disable the HTTP subsystem (optional, defaults to 'no')
me = peer1 ; Identifies this peer among the shardcache nodes
; which are defined in the [nodes] section
;user = username ; Assume the identity of 'username' (only when run as root)
pidfile = /var/run/shardcached.pid ; File where to store the pid of the running instance (optional)
; the nodes taking part in the shardcache (required)
[nodes]
peer1 = my_address:4444
peer2 = some_peer:4445
peer3 = some_other_peer:4446
[shardcache]
num_workers = 50 ; Number of shardcache workers (optional, defaults to '10')
evict_on_delete = yes ; Evict on delete (optional, defaults to 'yes')
use_persistent_connections = yes ; Use persistent connections instead of creating a new connection
force_caching = no ; Always cache remote items instead of applying a 10% chance (optional, defaults to 'no')
; for each command sent to peers
tcp_timeout = 0 ; Set the tcp timeout for all the outgoing connections
; (optional, a 0 value will make libshardcache use the compile-time default)
; (if set to 0 or omitted the libshardcache default timeout will be used)
conn_expire_time = 0 ; Set the connection expiration time in the pool, before triggering a NOOP to check connection validity.
; (optional, a 0 value will make libshardcache use the compile-time default)
; (if set to 0 or omitted the libshardcache default timeout will be used)
lazy_expiration = no ; Enable lazy expiration (optional, defaults to 'no')
expire_time = 0 ; Sets the global expiration time for cached items (optional, defaults to 0, items will never expire
; and will be removed from the cache only if explicitly/naturally evicted)
iomux_run_timeout_low = 0 ; Sets the low timeout (in microsecs) which will be passed to iomux_run() calls
; by both the serving workers and the async reader
; (optional, a 0 value will make libshardcache use the compile-time default)
iomux_run_timeout_high = 0 ; Sets the high timeout (in microsecs) which will be passed to iomux_run() calls
; by both the listener and the expirer
; (optional, a 0 value will make libshardcache use the compile-time default)
pipelining_max = 64 ; maximum number of requests to process ahead when pipelining
; (if omitted, the libshardcache compiled-in default will be used)
secret = default ; Shared secret used for message signing (optional, defaults to 'default')
[http]
listen = *:4321 ; HTTP address:port where to listen for incoming connections (optional)
num_workers = 50 ; Number of http worker threads (optional, defaults to '10')
access_log = ./shardcached_access.log ; Path to the acces_log file (optional)
basepath = shardcache ; Base http path (optional)
baseadminpath = admin ; Base http path for administrative pages (optional, will be the same as basepath if not defined)
acl_default = allow ; Default behavior for paths not matching any of those defined
; in the acl section. Possible values are : 'allow' , 'deny'
; (optional, defaults to 'allow')
[acl]
__(stats|index)__ = deny:*:*
.* = deny:PUT:*
.* = deny:DELETE:*
.* = allow:*:192.168.1.123/32
.* = allow:*:127.0.0.1/32
[mime-types]
pdf = application/pdf
ps = application/postscript
xml = application/xml
;js = application/javascript
json = application/json
gif = image/gif
jpeg = image/jpeg
jpg = image/jpeg
png = image/png
tiff = image/tiff
html = text/html
txt = text/plain
csv = text/csv
css = text/css
mpg = video/mpeg
mp4 = video/mp4