[BUG] If configuration file initialization fails, the configuration file remains uninitialized indefinitely

Is there an existing issue for this?

• I have searched the existing issues

SDK Version

3.2.0-alpha to 4.2.2.
Since this commit: Update HttpProjectConfigManager to use Last-Modified time (https://github.com/optimizely/java-sdk/pull/292)

Current Behavior

If the initialization of the configuration file fails, the configuration file remains un-initilialized indefinitely until the server/pod is restarted, or the configuration gets updated on Optimizely platform.

Expected Behavior

If the configuration file cannot be initialized at server start-up (eg: because Optimizely is down or takes to much time to respond), then during the next configuration poll, the configuration should be updated, even if Optimizely returns an HTTP 304 (Not Modified) code.

Steps To Reproduce

• At initialization of the PollingProjectConfigManager the connection is broken, or there is a time out, or an error. => PollingProjectConfigManager.currentProjectConfig is empty.
• 5min later, PollingProjectConfigManager.poll() polls the config file, but receives HTTP 304 from Optimizely => PollingProjectConfigManager.currentProjectConfig remains empty.
• 5min later, still no modification on the configuration => PollingProjectConfigManager.currentProjectConfig remains empty.
• PollingProjectConfigManager.currentProjectConfig is never initialized (except if a modification on the configuration is done on Optimizely side, or the server is restarted).

Java Version

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Link

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Logs

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Severity

Affecting users

Workaround/Solution

See the HttpProjectConfigManager:
https://github.com/optimizely/java-sdk/blob/746e81530a9224fabcd7f610d81800358e6e34c9/core-httpclient-impl/src/main/java/com/optimizely/ab/config/HttpProjectConfigManager.java#L95-L121

Here, the condition handling the HttpStatus.SC_NOT_MODIFIED should check if the currentProjectConfig is initialized or not. If it is empty, it means the configuration file has never been initialized properly and the configuration should thus be returned.

Recent Change

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Conflicts

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Start in core-httpclient-impl/src/main/java/com/optimizely/ab/config/HttpProjectConfigManager.java, especially the HttpStatus.SC_NOT_MODIFIED handling around lines 95–121. Trace how PollingProjectConfigManager initializes and polls currentProjectConfig after an HTTP 304. Done means a failed startup can initialize the configuration during a later poll even when the response is 304.