The FDv1 fallback directive parsed from a connection's response headers.
Its presence (fdv1Fallback === true) means the server asked the SDK to
fall back to FDv1.
fdv1FallbackTtlMs is how long to remain on FDv1 before retrying FDv2:
undefined: the server gave no TTL header (caller uses a 1-hour default).
0: indefinite fallback (no automatic recovery).
> 0: milliseconds to wait before attempting FDv2 recovery.
This is the single place that interprets x-ld-fd-fallback and
x-ld-fd-fallback-ttl.
The FDv1 fallback directive parsed from a connection's response headers. Its presence (
fdv1Fallback === true) means the server asked the SDK to fall back to FDv1.fdv1FallbackTtlMsis how long to remain on FDv1 before retrying FDv2:undefined: the server gave no TTL header (caller uses a 1-hour default).0: indefinite fallback (no automatic recovery).> 0: milliseconds to wait before attempting FDv2 recovery.This is the single place that interprets
x-ld-fd-fallbackandx-ld-fd-fallback-ttl.