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In Mariadb and Galera cluster, we have 3 nodes. I update a field from 99 to 100 through node 1. If I retrieve the same field through node 2, will I get 99 instead of 100 ?

Because the field is used as a sequence number to be part of a application number. It needs to be unique and less gap numbers as far as possible (in multi node environment). If there are gap numbers, it will use up the application number very soon (we use 5 digits as part of the application number)

I understand that a sequence will have gap numbers in mariadb and galera. Instead, I would try to write a function to increment by 1 in a field in a table. But not sure it will work in multi node environment e.g. problem to get different value from different nodes

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Its an "eventually consistent" system. Which means it is possible to get 99 back but eventually you'll get 100. IOW reads are not guaranteed to see the latest writes from other nodes immediately

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Thanks Krimson. So if i read 99 through node 2, can I update the value to 100 in node 2 ? Or it will wait for the replication from node 1 first and no allow me to update to 100 in node 2 ? Or it allows me to update in node 2 but what will happen if node 2 get the replication from node 1 to update to 100 ?
I will keep using node 1 constantly. When node 1 is in problem, then failover to use node 2. But my worry is that when fail over to node 2, will it first perform the changes in node 1, after that to allow the application to update the table ? (node 1 and node 2 are active active mode) . Thanks.
Yes it will allow you, latest writes win

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