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Neil Twigg
e373290d76
Otherwise this can potentially result in a deadlock if interleaving with certain other operations, i.e. stream purges, new consumer assignments. Signed-off-by: Neil Twigg <[email protected]>
37 lines
1.4 KiB
Plaintext
37 lines
1.4 KiB
Plaintext
Here is the list of some established lock ordering.
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In this list, A -> B means that you can have A.Lock() then B.Lock(), not the opposite.
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jetStream -> jsAccount -> Server -> client -> Account
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jetStream -> jsAccount -> stream -> consumer
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A lock to protect jetstream account's usage has been introduced: jsAccount.usageMu.
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This lock is independent and can be invoked under any other lock: jsAccount -> jsa.usageMu, stream -> jsa.usageMu, etc...
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A lock to protect the account's leafnodes list was also introduced to
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allow that lock to be held and the acquire a client lock which is not
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possible with the normal account lock.
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accountLeafList -> client
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AccountResolver interface has various implementations, but assume: AccountResolver -> Server
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A reloadMu lock was added to prevent newly connecting clients racing with the configuration reload.
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This must be taken out as soon as a reload is about to happen before any other locks:
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reloadMu -> Server
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reloadMu -> optsMu
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The "jscmMu" lock in the Account is used to serialise calls to checkJetStreamMigrate and
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clearObserverState so that they cannot interleave which would leave Raft nodes in
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inconsistent observer states.
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jscmMu -> Account -> jsAccount
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jscmMu -> stream.clsMu
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jscmMu -> RaftNode
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The "clsMu" lock protects the consumer list on a stream, used for signalling consumer activity.
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stream -> clsMu
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