Integrity of write behind

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Coleman, JohnSteven (Agoda) Coleman, JohnSteven (Agoda)
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Integrity of write behind

Hi,

 

What happens if a node goes down while write behind is in progress on a cache that’s persisting to the database? Can the task of persistence be carried on exactly where it failed by a back up node? Are cache entries flagged when they have been successfully persisted so that another node can pick up the task later? Should the persistence layer keep a version number or similar so that updates are orderly and not duplicated?

 

John



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Denis Mekhanikov Denis Mekhanikov
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Re: Integrity of write behind

John,

Entries are queued for persisting only on primary nodes, so if it fails before writing all updates to the underlying database, then it will result in some entries not being written to the database at all.
This is the price for a better performance, that write behind provides.


Denis

пт, 17 мая 2019 г. в 06:02, Coleman, JohnSteven (Agoda) <[hidden email]>:

Hi,

 

What happens if a node goes down while write behind is in progress on a cache that’s persisting to the database? Can the task of persistence be carried on exactly where it failed by a back up node? Are cache entries flagged when they have been successfully persisted so that another node can pick up the task later? Should the persistence layer keep a version number or similar so that updates are orderly and not duplicated?

 

John



This message is confidential and is for the sole use of the intended recipient(s). It may also be privileged or otherwise protected by copyright or other legal rules. If you have received it by mistake please let us know by reply email and delete it from your system. It is prohibited to copy this message or disclose its content to anyone. Any confidentiality or privilege is not waived or lost by any mistaken delivery or unauthorized disclosure of the message. All messages sent to and from Agoda may be monitored to ensure compliance with company policies, to protect the company's interests and to remove potential malware. Electronic messages may be intercepted, amended, lost or deleted, or contain viruses.