# README
Gonsq
Work In Progress
Gonsq is a wrapper of go-nsq library.
This library is inspired by how Lyft Building an Adaptive, Multi-Tenant Stream Bus with Kafka and Golang and Flow Control architecture in envoy proxy.
Nsqio
Gonsq is not using standard nsq.Consumer and nsq.Producer, instead the library provides NSQConsumer and NSQProducer object to communicate directly with nsq.Consumer and nsq.Producer.
Some properties also added to the NSQConsumer object, for example concurrency. The concurrency information is used to inform the Gonsq about how many concurrent consumers that a given NSQConsumer want to run.
Design
Gonsq implements its own flow control on top of go-nsq library by using buffered channel. The messages that delivered to buffered channels, then consumed by internal gonsq-handler` which run using goroutines. This mechanism gives gonsq a way to communicate with each concurrent handlers to be able to control the queue flow.
Stats
The library is exposing some metrics for internal usage and might be useful for the user to send the metrics to some monitoring backend. The stats object is available through nsq.Message struct and passed to the message handler.
The exposed metrics are:
- Total Message Count: The total count of messages consumed by particular worker of
topicandchannel. - Total Error Count: The total count of error happens in particular worker of
topicandchannel. - Total Message In Buffer Count: The total count of buffer used in particular worker of
topicandchannel. This stat is used to determine whether a throttling mechanism need to be triggered or not. - Total Buffer Length: The total length of buffer available for particular worker of
topicandchannel - Total Concurrency: The total number of concurrency/woker for particular worker of
topicandchannel - Total Worker Count: The current total number of worker for particular worker of
topicandchannel. This stat will be useful if we have a mechanism to reduce/increase the number of worker based on condition. For now, this is used to determine the number of worker on startup and shutdown. - Throttled: The status of particular
topicandchannel, is the consumer is beingthrottledor not.
How To Use The Library
To use this library, the consumer must be created using nsq/nsqio.
TODO
- DNS: make it possible to specify a single addresss with host or single/multiple address with IP. If a single host is given, then resolve to host.