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Options

Options are passed to the client upon initialisation

const { DeepstreamClient } = require('@deepstream/client')
const client = deepstream( 'localhost:6020', {
  // custom deepstream options
  mergeStrategy: deepstream.LOCAL_WINS,
  subscriptionTimeout: 500,
})

You can finely tune deepstream to meet your specific requirements, including reconnection behaviour and granular timeouts.

General Configuration​

mergeStrategy​

A global merge strategy that is applied whenever two clients write to the same record at the same time. Can be overwritten on a per record level. Default merge strategies are exposed by the client constructor. It's also possible to write custom merge strategies as functions. You can find more on handling data conflicts here
Type: Function
Default: MERGE_STRATEGIES.REMOTE_WINS

reconnectIntervalIncrement​

Specifies the number of milliseconds by which the time until the next reconnection attempt will be incremented after every unsuccessful attempt.
E.g.for 1500: if the connection is lost,the client will attempt to reconnect immediately, if that fails it will try again after 1.5 seconds, if that fails it will try again after 3 seconds and so on...
Type: Number
Default: 4000

heartbeatInterval​

The number of milliseconds to wait before sending a heartbeat. If two heatbeats are missed in a row the client will consider the server to have disconnected and will close the connection in order to establish a new one.

tip

If client heartbeatInterval > 2 * server heartbeatInterval the client will be considered as disconnnected by the server if no other messages are sent.

Type: Number
Default: 30000

maxReconnectAttempts​

The number of reconnection attempts until the client gives up and declares the connection closed.
Type: Number
Default: 5

subscriptionTimeout​

The number of milliseconds that can pass after providing/unproviding a RPC or subscribing/unsubscribing/listening to a record or event before an error is thrown.
Type: Number
Default: 2000

recordReadAckTimeout​

The number of milliseconds from the moment client.record.getRecord() is called until an error is thrown since no ack message has been received.
Type: Number
Default: 1000

recordReadTimeout​

The number of milliseconds from the moment client.record.getRecord() is called until an error is thrown since no data has been received.
Type: Number
Default: 3000

recordDeleteTimeout​

The number of milliseconds from the moment record.delete() is called until an error is thrown since no delete ack message has been received. Please take into account that the deletion is only complete after the record has been deleted from both cache and storage.
Type: Number
Default: 3000

recordDiscardTimeout​

The number of milliseconds from the moment record.discard() is called until the record is definitely discarded. Take into account that this interval might lead to some inconsistencies and race conditions if not handled properly.
Type: Number
Default: 5000

offlineEnabled​

Enable offline record support using indexdb or localstorage to store data client side. Type: Boolean
Default: false

storageName​

Set client side offline storage engine, options are indexdb and localstorage. Localstorage in node requires installing node-localstorage or equivalent API Type: String
Default: indexdb

More​

See all options in source repo or access default options through the client:

// Access default options
const { Options } = require('@deepstream/client')