SDK is polling feature flags ignores background settings

[AdamGrzybkowski]

Describe the bug
SDK is polling feature flags with disableBackgroundUpdating set to true and it does ignore backgroundPollingIntervalMillis when in background.
This is how I build the the LDClient currently

return LDConfig.Builder()
            .setMobileKey({{key}})
            .setDisableBackgroundUpdating(true)
            .setBackgroundPollingIntervalMillis(Duration.ofHours(5).toMillis().toInt())
            .setPollingIntervalMillis(Duration.ofMinutes(20).toMillis().toInt())
            .setStream(false)
            .build()

To reproduce
Run the app with the LDClient pasted above.
I was using Charles Proxy to inspect network requests.

Expected behavior
SDK is not polling feature flags when disabled and it respects that background polling interval if enabled

Logs
See the request time. These were done when the app was in the background.

1	2

SDK version
2.13.0

OS/platform
Android 10

[gwhelanLD]

Hi @AdamGrzybkowski,

I'm unable to replicate this issue. Could you provide device logs either here, or to our support team to help you track down the issue?

Thanks,
@gwhelanLD

[AdamGrzybkowski]

LDConfig

LDConfig.Builder()
            .setMobileKey({{key}})
            .setBackgroundPollingIntervalMillis(Duration.ofHours(1).toMillis().toInt())
            .setPollingIntervalMillis(Duration.ofMinutes(5).toMillis().toInt())
            .setStream(false)
            .setDiagnosticOptOut(true)
            .build()

logs

2020-10-02 09:31:21.596 18915-18971/com.example.app D/SharedPrefsSummaryEventStore: Sending Summary Event: { example response }
2020-10-02 09:31:21.620 18915-18971/com.example.app D/DefaultEventProcessor$Consumer: Posting 3 event(s) to https://mobile.launchdarkly.com/mobile
2020-10-02 09:31:21.621 18915-18971/com.example.app D/DefaultEventProcessor$Consumer: Events body: [{}]
2020-10-02 09:31:23.602 18915-18915/com.example.app D/HttpFeatureFlagFetcher: Attempting to fetch Feature flags using uri: https://app.launchdarkly.com/msdk/evalx/users/{not sure if I can paste that}}
2020-10-02 09:31:23.604 18915-18915/com.example.app D/HttpFeatureFlagFetcher: Request{method=GET, url=https://app.launchdarkly.com/msdk/evalx/users/{not sure if I can paste that}, headers=[Authorization:api_key, User-Agent:AndroidClient/2.13.0]}
2020-10-02 09:31:23.849 18915-19078/com.example.app D/HttpFeatureFlagFetcher: Cache response: Response{protocol=http/1.1, code=200, message=, url=https://app.launchdarkly.com/msdk/evalx/users/{not sure if I can paste that}}
2020-10-02 09:31:23.851 18915-19078/com.example.app D/HttpFeatureFlagFetcher: Network response: Response{protocol=h2, code=304, message=, url=https://app.launchdarkly.com/msdk/evalx/users/{not sure if I can paste that}}
2020-10-02 09:31:38.284 18915-18915/com.example.app I/AppProcessObserver$onStop#invokeSuspend:29: ON_STOP
2020-10-02 09:36:21.589 18915-18971/com.example.app D/SharedPrefsSummaryEventStore: Sending Summary Event: { example response }
2020-10-02 09:36:21.593 18915-18971/com.example.app D/DefaultEventProcessor$Consumer: Posting 1 event(s) to https://mobile.launchdarkly.com/mobile
2020-10-02 09:36:21.594 18915-18971/com.example.app D/DefaultEventProcessor$Consumer: Events body: [{ example response }]
2020-10-02 09:41:21.588 18915-18971/com.example.app D/SharedPrefsSummaryEventStore: Sending Summary Event: { example response }
2020-10-02 09:41:21.592 18915-18971/com.example.app D/DefaultEventProcessor$Consumer: Posting 1 event(s) to https://mobile.launchdarkly.com/mobile
2020-10-02 09:41:21.593 18915-18971/com.example.app D/DefaultEventProcessor$Consumer: Events body: [{ example response }]
2020-10-02 09:46:21.588 18915-18971/com.example.app D/SharedPrefsSummaryEventStore: Sending Summary Event: { example response }
2020-10-02 09:46:21.591 18915-18971/com.example.app D/DefaultEventProcessor$Consumer: Posting 1 event(s) to https://mobile.launchdarkly.com/mobile
2020-10-02 09:46:21.592 18915-18971/com.example.app D/DefaultEventProcessor$Consumer: Events body: [{ example response }]

you can see that after ON_STOP the lib did 3 requests, each after 5 minutes
ON_STOP was logged when the app was backgrounded by turning off the screen.

Let me know if you need some other specific logs from the lib.

[AdamGrzybkowski]

another case but this time with background pooling disabled

LDConfig

LDConfig.Builder()
            .setMobileKey({{key}})
            .setDisableBackgroundUpdating(true)
            .setPollingIntervalMillis(Duration.ofMinutes(5).toMillis().toInt())
            .setStream(false)
            .setDiagnosticOptOut(true)
            .build()

logs

2020-10-02 10:52:18.290 23805-23868/com.example.app D/HttpFeatureFlagFetcher: Attempting to fetch Feature flags using uri: https://app.launchdarkly.com/msdk/evalx/users/...
2020-10-02 10:52:18.298 23805-23868/com.example.app D/HttpFeatureFlagFetcher: Request{method=GET, url=https://app.launchdarkly.com/msdk/evalx/users/..., headers=[Authorization:api_key , User-Agent:AndroidClient/2.13.0]}
2020-10-02 10:52:20.485 23805-23926/com.example.app D/HttpFeatureFlagFetcher: Cache response: Response{protocol=http/1.1, code=200, message=, url=https://app.launchdarkly.com/msdk/evalx/users/...}
2020-10-02 10:52:20.485 23805-23873/com.example.app D/HttpFeatureFlagFetcher: Cache response: Response{protocol=http/1.1, code=200, message=, url=https://app.launchdarkly.com/msdk/evalx/users/...}
2020-10-02 10:52:20.485 23805-23926/com.example.app D/HttpFeatureFlagFetcher: Network response: Response{protocol=h2, code=304, message=, url=https://app.launchdarkly.com/msdk/evalx/users/...}
2020-10-02 10:52:20.485 23805-23873/com.example.app D/HttpFeatureFlagFetcher: Network response: Response{protocol=h2, code=304, message=, url=https://app.launchdarkly.com/msdk/evalx/users/...}
2020-10-02 10:57:16.062 23805-23872/com.example.app D/SharedPrefsSummaryEventStore: Sending Summary Event: {response}
2020-10-02 10:57:16.088 23805-23872/com.example.app D/DefaultEventProcessor$Consumer: Posting 3 event(s) to https://mobile.launchdarkly.com/mobile
2020-10-02 10:57:16.090 23805-23872/com.example.app D/DefaultEventProcessor$Consumer: Events body: [{repsonse}]
2020-10-02 10:58:16.407 23805-23805/com.example.app I/AppProcessObserver$onStop#invokeSuspend:29: ON_STOP
2020-10-02 11:02:16.052 23805-23872/com.example.app D/SharedPrefsSummaryEventStore: Sending Summary Event: {response}
2020-10-02 11:02:16.055 23805-23872/com.example.app D/DefaultEventProcessor$Consumer: Posting 1 event(s) to https://mobile.launchdarkly.com/mobile
2020-10-02 11:02:16.056 23805-23872/com.example.app D/DefaultEventProcessor$Consumer: Events body: [{response}]
2020-10-02 11:07:16.051 23805-23872/com.example.app D/SharedPrefsSummaryEventStore: Sending Summary Event: {response}
2020-10-02 11:07:16.055 23805-23872/com.example.app D/DefaultEventProcessor$Consumer: Posting 1 event(s) to https://mobile.launchdarkly.com/mobile
2020-10-02 11:07:16.056 23805-23872/com.example.app D/DefaultEventProcessor$Consumer: Events body: [{response}]

same thing, even though the background polling is disabled, you can notice 2 reqestes after the app was backgrounded.

[gwhelanLD]

Ah, I think I see what I missed before. This appears to be a simple misunderstanding. The requests to mobile.launchdarkly.com are event posts, not flag polls. In polling mode, the event post interval is inherited from the polling interval if not explicitly set. Event posts will always be sent at the interval if events have been recorded since the previous post. So if flags are still being evaluated in the background, events will still be sent at the eventsFlushIntervalMillis, or if unset pollingIntervalMillis.

I hope this clears up the behavior. I'm going to close the issue as it does not seem to be a bug in the SDK.

Thanks,
@gwhelanLD