1. In redo() we save the old state.
2. If we do redo() for the same operation twice, the old state will be
overritten with the new one.
3. This in turn affects undo() and subsequent isAncestor() check.
Signed-off-by: Evgenii Stratonikov <e.stratonikov@yadro.com>
Memory forest is here to check the correctness of boltdb optimized
implementation. Let's keep it simple.
Signed-off-by: Evgenii Stratonikov <e.stratonikov@yadro.com>
Initially it was there to check whether an update is being initiated by
a proper node. It is now obsolete for 2 reasons:
1. Background synchronization fetches all operations from a single node.
2. There are a lot more problems with trust in the tree service, it is
only used in controlled environments.
Signed-off-by: Evgenii Stratonikov <e.stratonikov@yadro.com>
To achieve high performance we must choose proper values for both
batch size and delay. For user operations we want to set low delay.
However it would prevent tree synchronization operations to form big
enough batches. For these operations, batching gives the most benefit
not only in terms of on-CPU execution cost, but also by speeding up
transaction persist (`fsync`).
In this commit we try merging batches that are already
_triggered_, but not yet _started to execute_. This way we can still
query batches for execution after the provided delay while also allowing
multiple formed batches to execute faster.
Signed-off-by: Evgenii Stratonikov <e.stratonikov@yadro.com>
1. Reduce allocations inside transactions.
2. Do not encode container ID to string: it allocates a lot and takes more
space.
Signed-off-by: Evgenii Stratonikov <e.stratonikov@yadro.com>
Under high load we are limited by the _amount_ of keys we need to update
in a single transaction. In this commit we try storing all state
with a single key.
Signed-off-by: Evgenii Stratonikov <e.stratonikov@yadro.com>
It should be similar to a `TreeAddByPath`. `applyOperation` is used for
`Apply` when the operation can be inserted in the middle of a log.
Signed-off-by: Evgenii Stratonikov <e.stratonikov@yadro.com>
Because synchronization _most likely_ will have apply already existing
operations, it is much faster to check their presence in a read
transaction. However, always doing this will degrade the perfomance
for normal `Apply`. And, let's be honest, it is already not good.
Thus we add a separate parameter which specifies whether this logic is
enabled.
Signed-off-by: Evgenii Stratonikov <e.stratonikov@yadro.com>
Node children are not sorted and could occur in any order.
Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>
Signed-off-by: Evgenii Stratonikov <evgeniy@morphbits.ru>
Currently there is a possibility for modifying operations to fail
because of I/O errors and a new tree to be created on another shard.
This commit adds existence check for modifying operations.
Read operations remain as they are, not to slow things.
`TreeDrop` is an exception, because this is a tree removal and trying
multiple shards is not an unwanted behaviour.
Signed-off-by: Evgenii Stratonikov <evgeniy@morphbits.ru>
All logic errors are wrapped in `logicerr.Logical` type and do not
affect shard error counter.
Signed-off-by: Evgenii Stratonikov <evgeniy@morphbits.ru>
Do not return backend type from the service for now, because memory
backend is expected to vanish.
Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>
