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Posted to user@ratis.apache.org by Pietro Tollot <pt...@icloud.com> on 2021/01/20 16:04:43 UTC
applyTransaction of BaseStateMachine
Hi all, i have a doubt about the use of the applyTransaction method of a BaseStateMachine, my doubt regards when the methods is called, it is done once the cluster has committed a message or before to commit a message? That is a message is committed once applyTransaction has been performed in the majority of nodes?
Thanks,
Pietro
Re: applyTransaction of BaseStateMachine
Posted by Tsz Wo Sze <sz...@gmail.com>.
We may use DivisionInfo.getLastAppliedIndex() to get the last log index
already applied by the state machine. Use
RaftServer.getDivision().getInfo(groupId) to get the DivisionInfo of the
group.
Tsz-Wo
On Thu, Jan 21, 2021 at 3:14 AM Pietro Tollot <pt...@icloud.com> wrote:
> Maybe there is a misunderstanding, what i wanted to say is “that is if on
> a node i can know if all the transaction committed has been applied” on
> that node
>
> On 20 Jan 2021, at 20:11, Pietro Tollot <pt...@icloud.com> wrote:
>
> Yes, i have a component that has 2 passive replicas. The component process
> data, update the state and at certain intervals commit the new state, when
> the active replica fails a leader election mechanism elect one of the
> passive that start to process data. The problem is when the active replica
> commit the state and then fail and the elected replica start processing
> data without having applied the last transaction that has been committed,
> when this last transaction will be applied i will lose the data processes
> in between.
> I saw that there is in BaseStateMachine a method getLastAppliedTermIndex()
> that should return the last applied term, that is half of the work, the
> other half would be to know the last commit term index,
>
> Thanks
>
> On 20 Jan 2021, at 19:58, Rui Wang <am...@apache.org> wrote:
>
> I think Right now in Ratis you cannot know that on a node: applying
> transactions are asynchronous on each node. It's hard to estimate and it is
> also very costly to sync such information among nodes.
>
> BTW, is there a use case in your mind that you need to know this
> information?
>
> -Rui
>
> On Wed, Jan 20, 2021 at 10:51 AM Pietro Tollot <pt...@icloud.com> wrote:
>
>> Thanks for answering, what i meant was all the transactions of a commit
>> on Ratis nodes, that is if on a node i can know if all the transaction
>> committed has been applied,
>>
>> thanks
>>
>> On 20 Jan 2021, at 19:36, Rui Wang <am...@apache.org> wrote:
>>
>> > all the transactions has been applied
>>
>> Can you clarify what you mean by "all" the transaction? Is it mean all
>> transactions of a commit on Ratis nodes or all transactions in the raft log
>> in a single Ratis node?
>>
>>
>> -Rui
>>
>> On Wed, Jan 20, 2021 at 9:51 AM Pietro Tollot <pt...@icloud.com> wrote:
>>
>>> Thanks very much for the answer, is there a method to know if all the
>>> transactions has been applied?
>>>
>>> Thanks
>>>
>>> On 20 Jan 2021, at 17:47, Tsz Wo Sze <sz...@gmail.com> wrote:
>>>
>>> Hi Pietro,
>>>
>>> The applyTransaction method is called once the transaction has been
>>> committed.
>>> A transaction is committed once it has been replicated (not applied) to
>>> a majority of nodes.
>>>
>>> Hope it helps.
>>> Tsz-Wo
>>>
>>>
>>> On Thu, Jan 21, 2021 at 12:04 AM Pietro Tollot <pt...@icloud.com>
>>> wrote:
>>>
>>>> Hi all, i have a doubt about the use of the applyTransaction method of
>>>> a BaseStateMachine, my doubt regards when the methods is called, it is done
>>>> once the cluster has committed a message or before to commit a message?
>>>> That is a message is committed once applyTransaction has been performed in
>>>> the majority of nodes?
>>>>
>>>> Thanks,
>>>> Pietro
>>>
>>>
>>>
>>
>
>
Re: applyTransaction of BaseStateMachine
Posted by Pietro Tollot <pt...@icloud.com>.
Maybe there is a misunderstanding, what i wanted to say is “that is if on a node i can know if all the transaction committed has been applied” on that node
> On 20 Jan 2021, at 20:11, Pietro Tollot <pt...@icloud.com> wrote:
>
> Yes, i have a component that has 2 passive replicas. The component process data, update the state and at certain intervals commit the new state, when the active replica fails a leader election mechanism elect one of the passive that start to process data. The problem is when the active replica commit the state and then fail and the elected replica start processing data without having applied the last transaction that has been committed, when this last transaction will be applied i will lose the data processes in between.
> I saw that there is in BaseStateMachine a method getLastAppliedTermIndex() that should return the last applied term, that is half of the work, the other half would be to know the last commit term index,
>
> Thanks
>
>> On 20 Jan 2021, at 19:58, Rui Wang <amaliujia@apache.org <ma...@apache.org>> wrote:
>>
>> I think Right now in Ratis you cannot know that on a node: applying transactions are asynchronous on each node. It's hard to estimate and it is also very costly to sync such information among nodes.
>>
>> BTW, is there a use case in your mind that you need to know this information?
>>
>> -Rui
>>
>> On Wed, Jan 20, 2021 at 10:51 AM Pietro Tollot <ptollot@icloud.com <ma...@icloud.com>> wrote:
>> Thanks for answering, what i meant was all the transactions of a commit on Ratis nodes, that is if on a node i can know if all the transaction committed has been applied,
>>
>> thanks
>>
>>> On 20 Jan 2021, at 19:36, Rui Wang <amaliujia@apache.org <ma...@apache.org>> wrote:
>>>
>>> > all the transactions has been applied
>>>
>>> Can you clarify what you mean by "all" the transaction? Is it mean all transactions of a commit on Ratis nodes or all transactions in the raft log in a single Ratis node?
>>>
>>>
>>> -Rui
>>>
>>> On Wed, Jan 20, 2021 at 9:51 AM Pietro Tollot <ptollot@icloud.com <ma...@icloud.com>> wrote:
>>> Thanks very much for the answer, is there a method to know if all the transactions has been applied?
>>>
>>> Thanks
>>>
>>>> On 20 Jan 2021, at 17:47, Tsz Wo Sze <szetszwo@gmail.com <ma...@gmail.com>> wrote:
>>>>
>>>> Hi Pietro,
>>>>
>>>> The applyTransaction method is called once the transaction has been committed.
>>>> A transaction is committed once it has been replicated (not applied) to a majority of nodes.
>>>>
>>>> Hope it helps.
>>>> Tsz-Wo
>>>>
>>>>
>>>> On Thu, Jan 21, 2021 at 12:04 AM Pietro Tollot <ptollot@icloud.com <ma...@icloud.com>> wrote:
>>>> Hi all, i have a doubt about the use of the applyTransaction method of a BaseStateMachine, my doubt regards when the methods is called, it is done once the cluster has committed a message or before to commit a message? That is a message is committed once applyTransaction has been performed in the majority of nodes?
>>>>
>>>> Thanks,
>>>> Pietro
>>>
>>
>
Re: applyTransaction of BaseStateMachine
Posted by Pietro Tollot <pt...@icloud.com>.
Yes, i have a component that has 2 passive replicas. The component process data, update the state and at certain intervals commit the new state, when the active replica fails a leader election mechanism elect one of the passive that start to process data. The problem is when the active replica commit the state and then fail and the elected replica start processing data without having applied the last transaction that has been committed, when this last transaction will be applied i will lose the data processes in between.
I saw that there is in BaseStateMachine a method getLastAppliedTermIndex() that should return the last applied term, that is half of the work, the other half would be to know the last commit term index,
Thanks
> On 20 Jan 2021, at 19:58, Rui Wang <am...@apache.org> wrote:
>
> I think Right now in Ratis you cannot know that on a node: applying transactions are asynchronous on each node. It's hard to estimate and it is also very costly to sync such information among nodes.
>
> BTW, is there a use case in your mind that you need to know this information?
>
> -Rui
>
> On Wed, Jan 20, 2021 at 10:51 AM Pietro Tollot <ptollot@icloud.com <ma...@icloud.com>> wrote:
> Thanks for answering, what i meant was all the transactions of a commit on Ratis nodes, that is if on a node i can know if all the transaction committed has been applied,
>
> thanks
>
>> On 20 Jan 2021, at 19:36, Rui Wang <amaliujia@apache.org <ma...@apache.org>> wrote:
>>
>> > all the transactions has been applied
>>
>> Can you clarify what you mean by "all" the transaction? Is it mean all transactions of a commit on Ratis nodes or all transactions in the raft log in a single Ratis node?
>>
>>
>> -Rui
>>
>> On Wed, Jan 20, 2021 at 9:51 AM Pietro Tollot <ptollot@icloud.com <ma...@icloud.com>> wrote:
>> Thanks very much for the answer, is there a method to know if all the transactions has been applied?
>>
>> Thanks
>>
>>> On 20 Jan 2021, at 17:47, Tsz Wo Sze <szetszwo@gmail.com <ma...@gmail.com>> wrote:
>>>
>>> Hi Pietro,
>>>
>>> The applyTransaction method is called once the transaction has been committed.
>>> A transaction is committed once it has been replicated (not applied) to a majority of nodes.
>>>
>>> Hope it helps.
>>> Tsz-Wo
>>>
>>>
>>> On Thu, Jan 21, 2021 at 12:04 AM Pietro Tollot <ptollot@icloud.com <ma...@icloud.com>> wrote:
>>> Hi all, i have a doubt about the use of the applyTransaction method of a BaseStateMachine, my doubt regards when the methods is called, it is done once the cluster has committed a message or before to commit a message? That is a message is committed once applyTransaction has been performed in the majority of nodes?
>>>
>>> Thanks,
>>> Pietro
>>
>
Re: applyTransaction of BaseStateMachine
Posted by Rui Wang <am...@apache.org>.
I think Right now in Ratis you cannot know that on a node: applying
transactions are asynchronous on each node. It's hard to estimate and it is
also very costly to sync such information among nodes.
BTW, is there a use case in your mind that you need to know this
information?
-Rui
On Wed, Jan 20, 2021 at 10:51 AM Pietro Tollot <pt...@icloud.com> wrote:
> Thanks for answering, what i meant was all the transactions of a commit on
> Ratis nodes, that is if on a node i can know if all the transaction
> committed has been applied,
>
> thanks
>
> On 20 Jan 2021, at 19:36, Rui Wang <am...@apache.org> wrote:
>
> > all the transactions has been applied
>
> Can you clarify what you mean by "all" the transaction? Is it mean all
> transactions of a commit on Ratis nodes or all transactions in the raft log
> in a single Ratis node?
>
>
> -Rui
>
> On Wed, Jan 20, 2021 at 9:51 AM Pietro Tollot <pt...@icloud.com> wrote:
>
>> Thanks very much for the answer, is there a method to know if all the
>> transactions has been applied?
>>
>> Thanks
>>
>> On 20 Jan 2021, at 17:47, Tsz Wo Sze <sz...@gmail.com> wrote:
>>
>> Hi Pietro,
>>
>> The applyTransaction method is called once the transaction has been
>> committed.
>> A transaction is committed once it has been replicated (not applied) to a
>> majority of nodes.
>>
>> Hope it helps.
>> Tsz-Wo
>>
>>
>> On Thu, Jan 21, 2021 at 12:04 AM Pietro Tollot <pt...@icloud.com>
>> wrote:
>>
>>> Hi all, i have a doubt about the use of the applyTransaction method of a
>>> BaseStateMachine, my doubt regards when the methods is called, it is done
>>> once the cluster has committed a message or before to commit a message?
>>> That is a message is committed once applyTransaction has been performed in
>>> the majority of nodes?
>>>
>>> Thanks,
>>> Pietro
>>
>>
>>
>
Re: applyTransaction of BaseStateMachine
Posted by Pietro Tollot <pt...@icloud.com>.
Thanks for answering, what i meant was all the transactions of a commit on Ratis nodes, that is if on a node i can know if all the transaction committed has been applied,
thanks
> On 20 Jan 2021, at 19:36, Rui Wang <am...@apache.org> wrote:
>
> > all the transactions has been applied
>
> Can you clarify what you mean by "all" the transaction? Is it mean all transactions of a commit on Ratis nodes or all transactions in the raft log in a single Ratis node?
>
>
> -Rui
>
> On Wed, Jan 20, 2021 at 9:51 AM Pietro Tollot <ptollot@icloud.com <ma...@icloud.com>> wrote:
> Thanks very much for the answer, is there a method to know if all the transactions has been applied?
>
> Thanks
>
>> On 20 Jan 2021, at 17:47, Tsz Wo Sze <szetszwo@gmail.com <ma...@gmail.com>> wrote:
>>
>> Hi Pietro,
>>
>> The applyTransaction method is called once the transaction has been committed.
>> A transaction is committed once it has been replicated (not applied) to a majority of nodes.
>>
>> Hope it helps.
>> Tsz-Wo
>>
>>
>> On Thu, Jan 21, 2021 at 12:04 AM Pietro Tollot <ptollot@icloud.com <ma...@icloud.com>> wrote:
>> Hi all, i have a doubt about the use of the applyTransaction method of a BaseStateMachine, my doubt regards when the methods is called, it is done once the cluster has committed a message or before to commit a message? That is a message is committed once applyTransaction has been performed in the majority of nodes?
>>
>> Thanks,
>> Pietro
>
Re: applyTransaction of BaseStateMachine
Posted by Rui Wang <am...@apache.org>.
> all the transactions has been applied
Can you clarify what you mean by "all" the transaction? Is it mean all
transactions of a commit on Ratis nodes or all transactions in the raft log
in a single Ratis node?
-Rui
On Wed, Jan 20, 2021 at 9:51 AM Pietro Tollot <pt...@icloud.com> wrote:
> Thanks very much for the answer, is there a method to know if all the
> transactions has been applied?
>
> Thanks
>
> On 20 Jan 2021, at 17:47, Tsz Wo Sze <sz...@gmail.com> wrote:
>
> Hi Pietro,
>
> The applyTransaction method is called once the transaction has been
> committed.
> A transaction is committed once it has been replicated (not applied) to a
> majority of nodes.
>
> Hope it helps.
> Tsz-Wo
>
>
> On Thu, Jan 21, 2021 at 12:04 AM Pietro Tollot <pt...@icloud.com> wrote:
>
>> Hi all, i have a doubt about the use of the applyTransaction method of a
>> BaseStateMachine, my doubt regards when the methods is called, it is done
>> once the cluster has committed a message or before to commit a message?
>> That is a message is committed once applyTransaction has been performed in
>> the majority of nodes?
>>
>> Thanks,
>> Pietro
>
>
>
Re: applyTransaction of BaseStateMachine
Posted by Pietro Tollot <pt...@icloud.com>.
Thanks very much for the answer, is there a method to know if all the transactions has been applied?
Thanks
> On 20 Jan 2021, at 17:47, Tsz Wo Sze <sz...@gmail.com> wrote:
>
> Hi Pietro,
>
> The applyTransaction method is called once the transaction has been committed.
> A transaction is committed once it has been replicated (not applied) to a majority of nodes.
>
> Hope it helps.
> Tsz-Wo
>
>
> On Thu, Jan 21, 2021 at 12:04 AM Pietro Tollot <ptollot@icloud.com <ma...@icloud.com>> wrote:
> Hi all, i have a doubt about the use of the applyTransaction method of a BaseStateMachine, my doubt regards when the methods is called, it is done once the cluster has committed a message or before to commit a message? That is a message is committed once applyTransaction has been performed in the majority of nodes?
>
> Thanks,
> Pietro
Re: applyTransaction of BaseStateMachine
Posted by Tsz Wo Sze <sz...@gmail.com>.
Hi Pietro,
The applyTransaction method is called once the transaction has been
committed.
A transaction is committed once it has been replicated (not applied) to a
majority of nodes.
Hope it helps.
Tsz-Wo
On Thu, Jan 21, 2021 at 12:04 AM Pietro Tollot <pt...@icloud.com> wrote:
> Hi all, i have a doubt about the use of the applyTransaction method of a
> BaseStateMachine, my doubt regards when the methods is called, it is done
> once the cluster has committed a message or before to commit a message?
> That is a message is committed once applyTransaction has been performed in
> the majority of nodes?
>
> Thanks,
> Pietro