nsqd

nsqd

nsqd is the daemon that receives, buffers, and delivers messages to clients.

It can be run and used standalone but is normally configured to talk to with nsqlookupd instance(s) in which case it will announce topic and channels for discovery.

It listens on two TCP ports, one for clients and another for the HTTP API.

HTTP API

• /put?topic=... - POST message body, ie $ curl -d "<message>" http://127.0.0.1:4151/put?topic=message_topic
• /mput?topic=... - POST message body (\n separated, TODO: it is incompatible with binary message formats)
• /create_channel?topic=...&channel=...
• /delete_channel?topic=...&channel=...
• /empty_channel?topic=...&channel=...
• /pause_channel?topic=...&channel=...
• /unpause_channel?topic=...&channel=...
• /create_topic?topic=...
• /delete_topic?topic=...
• /empty_topic?topic=...
• /stats - supports both text (default) and JSON via ?format=json
• /ping - returns OK (useful for monitoring)
• /info - returns version information

Command Line Options

-broadcast-address="": address that will be registered with lookupd, (default to the OS hostname)
-data-path="": path to store disk-backed messages
-http-address="0.0.0.0:4151": <addr>:<port> to listen on for HTTP clients
-lookupd-tcp-address=[]: lookupd TCP address (may be given multiple times)
-max-body-size=5123840: maximum size of a single command body
-max-bytes-per-file=104857600: number of bytes per diskqueue file before rolling
-max-heartbeat-interval=1m0s: maximum duration of time between heartbeats that a client can configure
-max-message-size=1024768: maximum size of a single message in bytes
-max-msg-timeout=15m0s: maximum duration before a message will timeout
-max-rdy-count=2500: maximum RDY count for a single client
-mem-queue-size=10000: number of messages to keep in memory (per topic/channel)
-msg-timeout="60s": duration to wait before auto-requeing a message
-statsd-address="": UDP <addr>:<port> of a statsd daemon for writing stats
-statsd-interval=30: seconds between pushing to statsd
-sync-every=2500: number of messages between diskqueue syncs
-tcp-address="0.0.0.0:4150": <addr>:<port> to listen on for TCP clients
-verbose=false: enable verbose logging
-version=false: print version string
-worker-id=0: unique identifier (int) for this worker (will default to a hash of hostname)

Statsd / Graphite Integration

When using --statsd-address specify the UDP <addr>:<port> for statsd (or a port of statsd like gographite), nsqd will push metrics to statsd periodically based on the interval specified in --statsd-interval. With this enabled nsqadmin can be configured to display charts directly from graphite.

We recommend the following configuration for graphite storage-schemas.conf

[nsq]
pattern = ^nsq\..*
retentions = 1m:1d,5m:30d,15m:1y

And the following for storage-aggregation.conf

[default_nsq]
pattern = ^nsq\..*
xFilesFactor = 0.2 
aggregationMethod = average