Alessandro/auto reconnect server side - #5788
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Adds the two server-side changes needed for SDK auto-reconnect (proposal 0037). Connection replacement: a client which reconnects can now send a stable, client-generated `session_id` query parameter. Each connection still gets its own ConnectionId and its own lifecycle events. The session id only identifies which earlier connection a new one supersedes. When a connection claims a session held by a live connection of the same identity, that connection's actor is stopped and its module-side disconnect lifecycle is awaited before the new connection's client_connected, so a module never observes two live connections for one session, nor the old connection's client_disconnected after the new client_connected. Batch subscribe: SubscribeBatch and SubscribeBatchApplied register multiple query sets under one subscription-manager lock and evaluate them at a single transaction snapshot. No transaction update can interleave with the responses, so a reconnecting client can replay its subscriptions and reconcile its cache against a consistent snapshot. Per-set errors are reported in the response and the remaining sets still apply.
Adds a raw v3 websocket client to the smoketests so a test controls exactly which query parameters a connection sends, plus a connection-session module which logs the lifecycle reducers with their connection ids so ordering can be asserted. Covers: - a reconnect with the same session id supersedes the previous connection, with client_disconnected for the old connection strictly before client_connected for the new one - a different session id does not supersede - a connection without a session id is never superseded - repeated reconnects leave exactly one live connection - batch subscribe applies every set atomically, reporting per-set errors while the remaining sets still apply. Note that a superseded connection is stopped but is not sent a close frame, so its peer's socket stays half-open: a passive read hangs while a round-trip fails. The tests assert the round-trip, which is the guarantee the server actually makes.
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Description of Changes
Auto-Reconnect: Connection replacement and batch subscribe
Adds the two server-side changes needed for SDK auto-reconnect (proposal 0037).
Connection replacement: a client which reconnects can now send a stable, client-generated
session_idquery parameter. Each connection still gets its own ConnectionId and its own lifecycle events. The session id only identifies which earlier connection a new one supersedes. When a connection claims a session held by a live connection of the same identity, that connection's actor is stopped and its module-side disconnect lifecycle is awaited before the new connection's client_connected, so a module never observes two live connections for one session, nor the old connection's client_disconnected after the new client_connected.Batch subscribe: SubscribeBatch and SubscribeBatchApplied register multiple query sets under one subscription-manager lock and evaluate them at a single transaction snapshot. No transaction update can interleave with the responses, so a reconnecting client can replay its subscriptions and reconcile its cache against a consistent snapshot. Per-set errors are reported in the response and the remaining sets still apply.
API and ABI breaking changes
No API breaking change. New V3 websocket protocol message. New clients will not be able to send this to old servers.
Expected complexity level and risk
2
Testing