doc: clarify exception from modify function in ddata (#28079)

This commit is contained in:
Patrik Nordwall 2019-10-28 15:15:15 +01:00 committed by Johannes Rudolph
parent 4b9d5f0302
commit 6d722cc313
2 changed files with 8 additions and 0 deletions

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@ -101,6 +101,10 @@ You will always see your own writes. For example if you send two `Update` messag
changing the value of the same `key`, the `modify` function of the second message will changing the value of the same `key`, the `modify` function of the second message will
see the change that was performed by the first `Update` message. see the change that was performed by the first `Update` message.
It is possible to abort the `Update` when inspecting the state parameter that is passed in to
the `modify` function by throwing an exception. That happens before the update is performed and
a `Replicator.ModifyFailure` is sent back as reply.
In the `Update` message you can pass an optional request context, which the `Replicator` In the `Update` message you can pass an optional request context, which the `Replicator`
does not care about, but is included in the reply messages. This is a convenient does not care about, but is included in the reply messages. This is a convenient
way to pass contextual information (e.g. original sender) without having to use `ask` way to pass contextual information (e.g. original sender) without having to use `ask`

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@ -128,6 +128,10 @@ sent back. Note that a `Replicator.UpdateTimeout` reply does not mean that the u
or was rolled back. It may still have been replicated to some nodes, and will eventually or was rolled back. It may still have been replicated to some nodes, and will eventually
be replicated to all nodes with the gossip protocol. be replicated to all nodes with the gossip protocol.
It is possible to abort the `Update` when inspecting the state parameter that is passed in to
the `modify` function by throwing an exception. That happens before the update is performed and
a `Replicator.ModifyFailure` is sent back as reply.
### Get ### Get
To retrieve the current value of a data you send `Replicator.Get` message to the To retrieve the current value of a data you send `Replicator.Get` message to the