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PostgresQueueParameters

@webda/postgres

Class: PostgresQueueParameters

Defined in: postgres/src/postgresqueue.service.ts:11

Configuration for PostgresQueueService.

Extends​

  • QueueParameters

Constructors​

Constructor​

new PostgresQueueParameters(): PostgresQueueParameters

Returns​

PostgresQueueParameters

Inherited from​

QueueParameters.constructor

Properties​

autoCreateTable?​

optional autoCreateTable?: boolean

Defined in: postgres/src/postgresqueue.service.ts:60

Whether to auto-create the queue table on init.

Default​

true

batchSize?​

optional batchSize?: number

Defined in: postgres/src/postgresqueue.service.ts:39

Max number of messages pulled per receiveMessage call. The queue worker calls receiveMessage in a loop, so this is also the parallel batch size.

Default​

10

idleDelayer?​

optional idleDelayer?: WaitDelayerDefinition

Defined in: core/lib/queues/queueservice.d.ts:47

Delayer between two receives of the main consumer while the queue returns no message

Queues answering immediately when empty (PostgresQueue, AMQPQueue...) would otherwise be polled in a tight loop. The delay grows with the consecutive empty receives, up to maxIdleDelay; the time spent in the receive is deducted, so long-polling queues (SQSQueue, FileQueue, MemoryQueue with a timeout) are not slowed down.

Default​

{ "type": "exponential", "interval": 50 }

Inherited from​

QueueParameters.idleDelayer

maxConsumers​

maxConsumers: number

Defined in: core/lib/queues/queueservice.d.ts:37

Max number of queue consumers Queue will auto increase to this max number if queue is loaded and it will decrease to just one consumer if no messages are available

Default​

10

Inherited from​

QueueParameters.maxConsumers

maxIdleDelay?​

optional maxIdleDelay?: number

Defined in: core/lib/queues/queueservice.d.ts:56

Maximum delay between two receives while the queue stays empty, in milliseconds

It bounds the extra latency of the first message after an idle period, and the polling rate of an idle consumer (4 receives per second at 250ms).

Default​

250

Inherited from​

QueueParameters.maxIdleDelay

notify?​

optional notify?: boolean

Defined in: postgres/src/postgresqueue.service.ts:70

Wake up the consumers with LISTEN / NOTIFY instead of polling

sendMessage NOTIFYs a channel named after the table (lowercased), and consume() opens a dedicated LISTEN connection: once the queue is empty, its receives wait for a notification, up to waitTimeout, before querying again. Direct receiveMessage calls never wait. Set to false to poll as before.

Default​

true

postgresqlServer?​

optional postgresqlServer?: ClientConfig | PoolConfig

Defined in: postgres/src/postgresqueue.service.ts:54

Connection settings forwarded to the chosen pg client/pool. Defaults to PG* environment variables.

Can be encrypted with webda config encrypt

Secret​

password,connectionString

reconnectDelay?​

optional reconnectDelay?: number

Defined in: postgres/src/postgresqueue.service.ts:86

Reconnect delay in milliseconds when the LISTEN connection drops. A randomized jitter is added. Consumers poll while it is down.

Default​

500

table?​

optional table?: string

Defined in: postgres/src/postgresqueue.service.ts:22

Table name backing the queue. Auto-created on init if missing.

Default​

"webda_queue"

Pattern​

/^[a-zA-Z_][a-zA-Z0-9_]*$/

Examples​

"myapp_queue"
"user_notifications"
"cache_invalidation"
"orders"

type​

type: string

Defined in: core/lib/services/serviceparameters.d.ts:9

Type of the service

Inherited from​

QueueParameters.type

usePool?​

optional usePool?: boolean

Defined in: postgres/src/postgresqueue.service.ts:46

Whether to use a pg.Pool (recommended for shared workloads) or a single pg.Client.

Default​

true

visibilityTimeout?​

optional visibilityTimeout?: number

Defined in: postgres/src/postgresqueue.service.ts:31

Visibility timeout in seconds — how long a locked-but-undeleted message stays invisible to other consumers before being eligible for redelivery. Workers that crash mid-process without acking will see their messages reappear after this window.

Default​

30

waitTimeout?​

optional waitTimeout?: number

Defined in: postgres/src/postgresqueue.service.ts:79

Maximum time a receive of consume() waits for a notification, in seconds

The queue is queried at least that often, and at least every visibilityTimeout, as a safety net: it picks up the messages whose visibility lock expired, and the ones whose notification was missed.

Default​

20

workerDelayer?​

optional workerDelayer?: WaitDelayerDefinition

Defined in: core/lib/queues/queueservice.d.ts:24

Delayer between two failed attempts to process messages

Inherited from​

QueueParameters.workerDelayer

workerParallelism​

workerParallelism: boolean

Defined in: core/lib/queues/queueservice.d.ts:29

Define if worker should process multi message received in //

Default​

true

Inherited from​

QueueParameters.workerParallelism

Methods​

load()​

load(params?): this

Defined in: postgres/src/postgresqueue.service.ts:93

Parameters​

params?​

any = {}

the input parameters

Returns​

this

this

Overrides​

QueueParameters.load

update()​

update(params, delta): this

Defined in: core/lib/application/parameters.d.ts:21

Update parameters and call watchers if a parameter was changed

Parameters​

params​

any

the service parameters

delta​

any

the delta

Returns​

this

this for chaining

Inherited from​

QueueParameters.update

with()​

with(callback): this

Defined in: core/lib/application/parameters.d.ts:27

Watch for changes on the parameters and call watchers when a parameter is changed

Parameters​

callback​

(params) => void

the callback function

Returns​

this

this for chaining

Inherited from​

QueueParameters.with