[Subscribe]question about interval setting

[ymmemo]

Is it possible to set the sampling interval slower than the PublishingInterval?
Ex PublishingInterval 1s , SamplingInterval 2s
Will it make SamplingInterval=PublishingInterval＝1s in case of such a setting?

[magiconair]

Need to check. What do you expect to happen? Publish only happens after sampling.

[ymmemo]

In my opinion, ‘sampling interval slower than the PublishingInterval’ is unreasonable? but our setting is customized. I want to confirm what will happen to this setting and decide whether it needs to be restricted?

[magiconair]

Ok. You can check in subscribe.go what will happen. I think we only set the defaults and don't cover this case. What would be a reasonable behavior in your opinion?

[ymmemo]

In my opinion,Ex PublishingInterval 1s , SamplingInterval 2s,
I will not receive DataChangeNotification MonitoredItems by Publishing Interval(1s), because Sampling did not happen at some point.

Expected behavior:
DataChangeNotification(MonitoredItems) received by Sampling lingInterval(2s), because Sampling did not happen at some point.

Actual behavior:
DataChangeNotification(MonitoredItems received by Publishing lingInterval(1s) and all have value

[salmanazmat666]

In my opinion,Ex PublishingInterval 1s , SamplingInterval 2s, I will not receive DataChangeNotification MonitoredItems by Publishing Interval(1s), because Sampling did not happen at some point.

Expected behavior: DataChangeNotification(MonitoredItems) received by Sampling lingInterval(2s), because Sampling did not happen at some point.

Actual behavior: DataChangeNotification(MonitoredItems received by Publishing lingInterval(1s) and all have value

I'm seeing the expected behavior, notifications are received after roughly 2 sec.
The units of sampling interval are milliseconds, so you need the sampling interval to be 2000 in your example. If you set it to 2, then that'd be very fast for the server so the server sets revised sampling interval to a high value. Can you also check the revisedSamplingInterval in the response of your subscription.Monitor() function.

[ymmemo]

I didn't see RevisedSamplingInterval have any revised.

below is my Req/Res log:

**//CreateSubscriptionRequest**
  RequestHeader:  RequestHeader
    AuthenticationToken:    b=0gyJQUlnbyoWZYcbuWZ5X0fguOrb3yOABwZY9iXDONA=
    Timestamp:    2021-11-18 06:59:14.7696925 GMT
    RequestHandle:    8
    ReturnDiagnostics:    0
    AuditEntryId:    null
    TimeoutHint:    10000
    AdditionalHeader:    null
  **RequestedPublishingInterval:  1000.0**
  RequestedLifetimeCount:  RequestedMaxKeepAliveCount:  3000
  MaxNotificationsPerPublish:  PublishingEnabled:  true
  Priority:  0
**//CreateSubscriptionResponse**
  ResponseHeader:  ResponseHeader
    Timestamp:    2021-11-18 06:59:14.7530000 GMT
    RequestHandle:    8
    ServiceResult:    GOOD (0x00000000) ""
    ServiceDiagnostics:    null
    StringTable:    null
    AdditionalHeader:    null
  SubscriptionId:  3
  RevisedPublishingInterval:  1000.0
  RevisedLifetimeCount:  10000
  RevisedMaxKeepAliveCount:  3000
**//CreateMonitoredItemsRequest**
  RequestHeader:  RequestHeader
    AuthenticationToken:    b=0gyJQUlnbyoWZYcbuWZ5X0fguOrb3yOABwZY9iXDONA=
    Timestamp:    2021-11-18 06:59:14.7866807 GMT
    RequestHandle:    9
    ReturnDiagnostics:    0
    AuditEntryId:    null
    TimeoutHint:    10000
    AdditionalHeader:    null
  SubscriptionId:  3
  TimestampsToReturn:  Both
  ItemsToCreate:[0]:    MonitoredItemCreateRequest
      ItemToMonitor:      ReadValueId
        NodeId:        ns=3;i=1001
        AttributeId:        13
        IndexRange:        null
        DataEncoding:        null
      MonitoringMode:      Reporting
      RequestedParameters:      MonitoringParameters
        ClientHandle:        SamplingInterval:        2000.0
        Filter:        null
        QueueSize:        1
        DiscardOldest:        true
**//CreateMonitoredItemsResponse**
  ResponseHeader:  ResponseHeader
    Timestamp:    2021-11-18 06:59:14.7700000 GMT
    RequestHandle:    9
    ServiceResult:    GOOD (0x00000000) ""
    ServiceDiagnostics:    null
    StringTable:    null
    AdditionalHeader:    null
  Results:[0]:    MonitoredItemCreateResult
      StatusCode:      MonitoredItemId:      1
      RevisedSamplingInterval:      2000.0
      RevisedQueueSize:      FilterResult:      null
  DiagnosticInfos:  null


**//PublishRequest**
  RequestHeader:  RequestHeader
    AuthenticationToken:    b=0gyJQUlnbyoWZYcbuWZ5X0fguOrb3yOABwZY9iXDONA=
    Timestamp:    2021-11-18 06:59:14.8017332 GMT
    RequestHandle:    10
    ReturnDiagnostics:    0
    AuditEntryId:    null
    TimeoutHint:    3000000
    AdditionalHeader:    null
  SubscriptionAcknowledgements:
**//PublishResponse**
  ResponseHeader:  ResponseHeader
    Timestamp:    2021-11-18 06:59:15.7520000 GMT
    RequestHandle:    10
    ServiceResult:    GOOD (0x00000000) ""
    ServiceDiagnostics:    null
    StringTable:    null
    AdditionalHeader:    null
  SubscriptionId:  3
  AvailableSequenceNumbers:[0]:    1
  MoreNotifications:  false
  NotificationMessage:  NotificationMessage
    SequenceNumber:    PublishTime:    NotificationData:[0]:      ExtensionObject [typeId=nsu=http%3A%2F%2Fopcfoundation.org%2FUA%2F;i=811, encodeType=Binary, object=[38] 0x01000000000000000d0b00000000008072404073c6cc49dcd7018062cecc49dcd701ffffffff]
  Results:  DiagnosticInfos:  null
**//PublishRequest**
  RequestHeader:  RequestHeader
    AuthenticationToken:    b=0gyJQUlnbyoWZYcbuWZ5X0fguOrb3yOABwZY9iXDONA=
    Timestamp:    2021-11-18 06:59:15.7856205 GMT
    RequestHandle:    11
    ReturnDiagnostics:    0
    AuditEntryId:    null
    TimeoutHint:    3000000
    AdditionalHeader:    null
  SubscriptionAcknowledgements:[0]:    SubscriptionAcknowledgement
      SubscriptionId:      3
      SequenceNumber:      1
**//PublishResponse**
  ResponseHeader:  ResponseHeader
    Timestamp:    2021-11-18 06:59:16.7510000 GMT
    RequestHandle:    11
    ServiceResult:    GOOD (0x00000000) ""
    ServiceDiagnostics:    null
    StringTable:    null
    AdditionalHeader:    null
  SubscriptionId:  3
  AvailableSequenceNumbers:[0]:    2
  MoreNotifications:  false
  NotificationMessage:  NotificationMessage
    SequenceNumber:    PublishTime:    NotificationData:[0]:      ExtensionObject [typeId=nsu=http%3A%2F%2Fopcfoundation.org%2FUA%2F;i=811, encodeType=Binary, object=[38] 0x01000000000000000d0b0000000000207340c0095fcd49dcd701f0d166cd49dcd701ffffffff]
  Results:[0]:    null
  DiagnosticInfos:  null

[heaxo]

Hi @magiconair I would like to ask a question, does setting the interval frequency too high affect the performance of the server? How much should interval be set appropriately?