ConfigListener reports configuration load failure after deployment – Zend Framework 2 ModuleManager

Diagnosing a stale configuration cache in Zend Framework 2 deployments

Goal: Determine whether a failed deployment is caused by an outdated configuration cache after a code update, using only application logs.

Constraints: The Zend Framework 2 ModuleManager’s ConfigListener logs warnings about missing or unparsable configuration files, but it does not explicitly state whether the cache is stale or if an opcode cache is serving stale bytecode. Additionally, clearing the configuration cache on a production system may temporarily increase load, and the interaction with OPcache must be considered.

Uncertainty: It is unclear which log patterns definitively indicate a stale Zend configuration cache versus other configuration errors, and whether verifying timestamp mismatches alone is sufficient to confirm the root cause.

Specific questions:

• What exact log messages from Zend\ModuleManager\Listener\ConfigListener signal a stale configuration cache after deployment?
• How can one verify that clearing the Zend configuration cache resolves the deployment failure without needing to restart the opcode cache?
• Is comparing the modification timestamps of cached configuration files with their source module/config files a reliable method to confirm cache staleness in a production environment?