Protomux RPC Client Pool

Reliably connect to one of a pool of protomux-rpc servers.

Picks a random server to connect to, and keeps connecting to that server, unless it fails to respond, in which case it automatically switches over to another one.

Install

npm i protomux-rpc-client-pool

API

const pool = new ProtomuxRpcClientPool(keys, rpcClient, opts)

Create a new pool. keys is a list of HyperDHT servers that expose the same protomux-rpc service. rpcClient is a Protomux RPC client instance.

opts include:

• retries : the number of times to retry a request with a different server before giving up. Default: 3.
• rpcTimeout : the default timeout for a single request attempt, in ms.
• totalTimeout: the default timeout for the entire request, in ms. This timeout operates independently of rpcTimeout.
• rateLimit: bucket rate limit config
• ratelimit.capacity: max tokens (burst capacity). Set to -1 to disable the rate limit.
• ratelimit.intervalMs: time interval in milliseconds to refill 1 token

await pool.makeRequest(methodName, args, opts)

Makes a request for the specifed methodName to one of the servers in the pool, passing the args. If the server fails to respond, it automatically retries with other servers.

Throws a ProtomuxRpcClientPoolError.TOO_MANY_RETRIES error if the request attempt fails pool.retries times. Throws a ProtomuxRpcClientPoolError.POOL_REQUEST_TIMEOUT error if the request exceeds total timeout.

opts include:

• requestEncoding the request encoding of the RPC service
• responseEncoding the response encoding of the RPC service
• rpcTimeout the timeout to use for each request attempt (in ms). Defaults to pool.rpcTimeout.
• totalTimeout the timeout for entire request (in ms). Defaults to pool.totalTimeout.

pool.event(methodName, args, opts)

Creates a fire-and-forget event call to the currently selected server in the pool. The methodName and args parameters follow the same contract as pool.makeRequest(...).

opts include:

• requestEncoding the request encoding of the RPC service

pool.destroy()

Destroy the pool, cleanup the ratelimit