Question on the absolute time at the grid level

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egalois egalois
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Question on the absolute time at the grid level

Hello,

The context of this question is we would be using a grid composed out of
multiple nodes and it is very important the absolute time is the same on all
the nodes.

How is the time considered at the grid level? The time returned by issuing
/SELECT CURRENT_TIMESTAMP()/ would be the same on all the nodes or different
JDBC connections to different hosts would yield different results?

It may be possible nodes are residing on machines and there is an offset of
several minutes between machine system time values

What would Apache Ignite consider as CURRENT_TIMESTAMP() in the situations
above? And is there any way to control the time at the grid level?


Thank you


ilya.kasnacheev ilya.kasnacheev
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Re: Question on the absolute time at the grid level

Hello!

Ignite does not synchronize time on its nodes neither it depends on the time of nodes. If you need that functionality, you will need to do it yourself.

Regards,
--
Ilya Kasnacheev


пн, 30 сент. 2019 г. в 04:42, evariste galois <[hidden email]>:
Hello,

The context of this question is we would be using a grid composed out of
multiple nodes and it is very important the absolute time is the same on all
the nodes.

How is the time considered at the grid level? The time returned by issuing
/SELECT CURRENT_TIMESTAMP()/ would be the same on all the nodes or different
JDBC connections to different hosts would yield different results?

It may be possible nodes are residing on machines and there is an offset of
several minutes between machine system time values

What would Apache Ignite consider as CURRENT_TIMESTAMP() in the situations
above? And is there any way to control the time at the grid level?


Thank you


dmagda dmagda
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Re: Question on the absolute time at the grid level

In reply to this post by egalois
Hello, 

Could you please share more details on a business/technical task you're trying to solve? We might come up with some solution.

-
Denis


On Sun, Sep 29, 2019 at 6:42 PM evariste galois <[hidden email]> wrote:
Hello,

The context of this question is we would be using a grid composed out of
multiple nodes and it is very important the absolute time is the same on all
the nodes.

How is the time considered at the grid level? The time returned by issuing
/SELECT CURRENT_TIMESTAMP()/ would be the same on all the nodes or different
JDBC connections to different hosts would yield different results?

It may be possible nodes are residing on machines and there is an offset of
several minutes between machine system time values

What would Apache Ignite consider as CURRENT_TIMESTAMP() in the situations
above? And is there any way to control the time at the grid level?


Thank you


egalois egalois
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Re: Question on the absolute time at the grid level

Hello,

Basically, there is a modulle providing notifications upon certain expiration moments. Clients can manage timer objects which do expire at some point in the future. Different clients will use different nodes in the Ignite cluster so there will be errors if the clock is not aligned at the cluster level. I understood the suggested solution would be to enforce this for each of the machines nodes reside on.

Best Regards

On Wednesday, October 2, 2019, 7:16:22 AM GMT+8, Denis Magda <[hidden email]> wrote:


Hello, 

Could you please share more details on a business/technical task you're trying to solve? We might come up with some solution.

-
Denis


On Sun, Sep 29, 2019 at 6:42 PM evariste galois <[hidden email]> wrote:
Hello,

The context of this question is we would be using a grid composed out of
multiple nodes and it is very important the absolute time is the same on all
the nodes.

How is the time considered at the grid level? The time returned by issuing
/SELECT CURRENT_TIMESTAMP()/ would be the same on all the nodes or different
JDBC connections to different hosts would yield different results?

It may be possible nodes are residing on machines and there is an offset of
several minutes between machine system time values

What would Apache Ignite consider as CURRENT_TIMESTAMP() in the situations
above? And is there any way to control the time at the grid level?


Thank you