Reference documentation and code samples for the Compute Engine v1 API enum BackendServiceConnectionTrackingPolicy.Types.ConnectionPersistenceOnUnhealthyBackends.
Specifies connection persistence when backends are unhealthy. The default value is DEFAULT_FOR_PROTOCOL. If set to DEFAULT_FOR_PROTOCOL, the existing connections persist on unhealthy backends only for connection-oriented protocols (TCP and SCTP) and only if the Tracking Mode is PER_CONNECTION (default tracking mode) or the Session Affinity is configured for 5-tuple. They do not persist for UDP. If set to NEVER_PERSIST, after a backend becomes unhealthy, the existing connections on the unhealthy backend are never persisted on the unhealthy backend. They are always diverted to newly selected healthy backends (unless all backends are unhealthy). If set to ALWAYS_PERSIST, existing connections always persist on unhealthy backends regardless of protocol and session affinity. It is generally not recommended to use this mode overriding the default. For more details, see Connection Persistence for Network Load Balancing and Connection Persistence for Internal TCP/UDP Load Balancing.
[[["Easy to understand","easyToUnderstand","thumb-up"],["Solved my problem","solvedMyProblem","thumb-up"],["Other","otherUp","thumb-up"]],[["Missing the information I need","missingTheInformationINeed","thumb-down"],["Too complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-08 UTC."],[[["\u003cp\u003eThe latest version available for \u003ccode\u003eBackendServiceConnectionTrackingPolicy.Types.ConnectionPersistenceOnUnhealthyBackends\u003c/code\u003e is 3.6.0, with multiple previous versions also documented, starting from version 1.0.0.\u003c/p\u003e\n"],["\u003cp\u003eThis documentation provides reference information and code samples for the Compute Engine v1 API enum \u003ccode\u003eBackendServiceConnectionTrackingPolicy.Types.ConnectionPersistenceOnUnhealthyBackends\u003c/code\u003e.\u003c/p\u003e\n"],["\u003cp\u003eThe enum specifies connection persistence behavior when backends become unhealthy, with options including \u003ccode\u003eDEFAULT_FOR_PROTOCOL\u003c/code\u003e, \u003ccode\u003eNEVER_PERSIST\u003c/code\u003e, and \u003ccode\u003eALWAYS_PERSIST\u003c/code\u003e.\u003c/p\u003e\n"],["\u003cp\u003eThe \u003ccode\u003eDEFAULT_FOR_PROTOCOL\u003c/code\u003e setting allows existing connections to persist on unhealthy backends for TCP and SCTP protocols when tracking mode is \u003ccode\u003ePER_CONNECTION\u003c/code\u003e or Session Affinity is configured, while \u003ccode\u003eNEVER_PERSIST\u003c/code\u003e diverts connections to healthy backends, and \u003ccode\u003eALWAYS_PERSIST\u003c/code\u003e keeps existing connections regardless of health status.\u003c/p\u003e\n"],["\u003cp\u003eThere is an additional \u003ccode\u003eUndefinedConnectionPersistenceOnUnhealthyBackends\u003c/code\u003e field, which denotes a value indicating that the enum field is not set.\u003c/p\u003e\n"]]],[],null,[]]
