/ 
Net-Async-Redis-4.002
River stage one • 2 direct dependents • 2 total dependents
/ Net::Async::Redis::Cluster

NAME

Net::Async::Redis::Cluster - support for cluster routing

SYNOPSIS

use IO::Async::Loop;
use Net::Async::Redis::Cluster;
my $loop = IO::Async::Loop->new;
$loop->add(
 my $cluster = Net::Async::Redis::Cluster->new(
 )
);
await $cluster->bootstrap(
 host => 'redis.local',
);
print "Key: " . await $cluster->get('some_key');

DESCRIPTION

Provides access to a Redis cluster.

Usage is similar to Net::Async::Redis with the addition of a "bootstrap" step to find the initial client nodes:

$loop->add(
 my $cluster = Net::Async::Redis::Cluster->new(
 )
);
await $cluster->bootstrap(
 host => 'redis.local',
);
print "Key: " . await $cluster->get('some_key');

Note that this adds some overhead to lookups, so you may be better served by options such as the https://github.com/twitter/twemproxy|twemproxy proxy routing dæmon, or a service mesh such as https://istio.io/|istio.

METHODS

bootstrap

Connects to a Redis server and attempts to discover the cluster node configuration.

Usage:

try {
 await $cluster->bootstrap(
  host => 'redis-primary.local',
  port => 6379,
 );
} catch {
 $log->errorf('Unable to bootstrap the Redis cluster: %s', $@);
}

clientside_cache_events

Provides combined stream of clientside-cache events from all known Redis primary nodes.

watch_keyspace

"watch_keyspace" in Net::Async::Redis support for gathering notifications from all known nodes.

client_setname

Apply client name to all nodes.

Note that this only updates the current nodes, it will not apply to new nodes. Use the "client_name" in Net::Async::Redis constructor/"configure" parameter to apply to all nodes.

multi

A MULTI transaction on a Redis cluster works slightly differently from single-node setups.

  • issue MULTI on all nodes

  • execute the commands, distributing across nodes as usual

  • issue EXEC or DISCARD as appropriate

Note that the coderef is called only once, even if there are multiple nodes involved.

Currently, there's no optimisation for limiting MULTI to the nodes participating in the transaction.

METHODS - Internal

hash_slot_for_key

Calculates the CRC16 hash slot for the given key.

Note that keys are expected as bytestrings, if you have a Unicode string you'd likely want to convert to UTF-8 first.

replace_nodes

Swap the existing node configuration out for a new arrayref of nodes.

node_list

Returns a list of the currently-configured nodes.

node_for_slot

Returns the appropriate Net::Async::Redis::Cluster::Node for the given hash key (slot).

register_moved_slot

When we get MOVED error we will use this sub to rebuild the slot cache

apply_slots_from_instance

Connect to a random instance in the cluster and execute CLUSTER SLOTS to get information about the slots and their distribution.

execute_command

Lookup the correct node for the key then execute the command on that node, if there is a mismatch between our slot hashes and Redis's hashes we will attempt to rebuild the slot hashes and try again

ryu

A Ryu::Async instance for source/sink creation.

INHERITED METHODS

Net::Async::Redis::Commands

acl, acl_cat, acl_deluser, acl_dryrun, acl_genpass, acl_getuser, acl_list, acl_load, acl_log, acl_save, acl_setuser, acl_users, acl_whoami, append, asking, auth, bgrewriteaof, bgsave, bitcount, bitfield, bitfield_ro, bitop, bitpos, blmove, blmpop, blpop, brpop, brpoplpush, bzmpop, bzpopmax, bzpopmin, client, client_caching, client_getname, client_getredir, client_id, client_info, client_kill, client_list, client_no, client_no_evict, client_pause, client_reply, client_tracking, client_trackinginfo, client_unblock, client_unpause, cluster, cluster_addslots, cluster_addslotsrange, cluster_bumpepoch, cluster_count, cluster_count_failure, cluster_count_failure_reports, cluster_countkeysinslot, cluster_delslots, cluster_delslotsrange, cluster_failover, cluster_flushslots, cluster_forget, cluster_getkeysinslot, cluster_info, cluster_keyslot, cluster_links, cluster_meet, cluster_myid, cluster_nodes, cluster_replicas, cluster_replicate, cluster_reset, cluster_saveconfig, cluster_set, cluster_set_config, cluster_set_config_epoch, cluster_setslot, cluster_slaves, cluster_slots, command, command_count, command_docs, command_getkeys, command_getkeysandflags, command_info, command_list, config, config_get, config_resetstat, config_rewrite, config_set, copy, dbsize, decr, decrby, del, dump, echo, eval, eval_ro, evalsha, evalsha_ro, exists, expire, expireat, expiretime, failover, fcall, fcall_ro, flushall, flushdb, function, function_delete, function_dump, function_flush, function_kill, function_list, function_load, function_restore, function_stats, geoadd, geodist, geohash, geopos, georadius, georadius_ro, georadiusbymember, georadiusbymember_ro, geosearch, geosearchstore, get, getbit, getdel, getex, getrange, getset, hdel, hello, hexists, hget, hgetall, hincrby, hincrbyfloat, hkeys, hlen, hmget, hmset, hrandfield, hscan, hset, hsetnx, hstrlen, hvals, incr, incrby, incrbyfloat, info, keys, lastsave, latency, latency_doctor, latency_graph, latency_histogram, latency_history, latency_latest, latency_reset, lcs, lindex, linsert, llen, lmove, lmpop, lolwut, lpop, lpos, lpush, lpushx, lrange, lrem, lset, ltrim, memory, memory_doctor, memory_malloc, memory_malloc_stats, memory_purge, memory_stats, memory_usage, mget, migrate, module, module_list, module_load, module_unload, monitor, move, mset, msetnx, object, object_encoding, object_freq, object_idletime, object_refcount, persist, pexpire, pexpireat, pexpiretime, pfadd, pfcount, pfdebug, pfmerge, pfselftest, ping, psetex, psubscribe, psync, pttl, publish, pubsub, pubsub_channels, pubsub_numpat, pubsub_numsub, pubsub_shardchannels, pubsub_shardnumsub, punsubscribe, quit, randomkey, readonly, readwrite, rename, renamenx, replconf, replicaof, reset, restore, restore_asking, role, rpop, rpoplpush, rpush, rpushx, sadd, save, scan, scard, script, script_debug, script_exists, script_flush, script_kill, script_load, sdiff, sdiffstore, select, set, setbit, setex, setnx, setrange, shutdown, sinter, sintercard, sinterstore, sismember, slaveof, slowlog, slowlog_get, slowlog_len, slowlog_reset, smembers, smismember, smove, sort, sort_ro, spop, spublish, srandmember, srem, sscan, ssubscribe, strlen, subscribe, substr, sunion, sunionstore, sunsubscribe, swapdb, sync, time, touch, ttl, type, unlink, unsubscribe, unwatch, wait, watch, xack, xadd, xautoclaim, xclaim, xdel, xgroup, xgroup_create, xgroup_createconsumer, xgroup_delconsumer, xgroup_destroy, xgroup_setid, xinfo, xinfo_consumers, xinfo_groups, xinfo_stream, xlen, xpending, xrange, xread, xreadgroup, xrevrange, xsetid, xtrim, zadd, zcard, zcount, zdiff, zdiffstore, zincrby, zinter, zintercard, zinterstore, zlexcount, zmpop, zmscore, zpopmax, zpopmin, zrandmember, zrange, zrangebylex, zrangebyscore, zrangestore, zrank, zrem, zremrangebylex, zremrangebyrank, zremrangebyscore, zrevrange, zrevrangebylex, zrevrangebyscore, zrevrank, zscan, zscore, zunion, zunionstore

IO::Async::Notifier

add_child, adopt_future, adopted_futures, can_event, children, configure_unknown, debug_printf, get_loop, invoke_error, invoke_event, loop, make_event_cb, maybe_invoke_event, maybe_make_event_cb, new, notifier_name, parent, remove_child, remove_from_parent

AUTHOR

Tom Molesworth <TEAM@cpan.org> plus contributors as mentioned in "CONTRIBUTORS" in Net::Async::Redis.

LICENSE

Copyright Tom Molesworth and others 2015-2022. Licensed under the same terms as Perl itself.