Apache ignite node data loss recovery on node restart

Here,s the problem .

I started 6 ignite server nodes, loads the cache in them. queried using "dbeaver" it shows complete data in nodes. Now I shutdown one node . Queried by dbever, it shows less data. Now the same node I started again but data is still less.

How to resolve this ? I dont want to lose data when a node goes down. And if node is restarted then how to get the missing data.

I am loading cache from MySql db .

Solution

You don't give very much information about your cluster, so I'm guess that you're entirely in-memory and you're using the defaults for cache creation.

The default cache is partitioned (i.e., sharded), which is why you lose data when you shut down a node. You can, however, have backups.

<bean class="org.apache.ignite.configuration.IgniteConfiguration">
...
<property name="cacheConfiguration">
    <bean class="org.apache.ignite.configuration.CacheConfiguration">
        <!-- Set a cache name. -->
        <property name="name" value="cacheName"/>
        <!-- Set cache mode. -->
        <property name="cacheMode" value="PARTITIONED"/>
        <!-- Number of backup nodes. -->
        <property name="backups" value="1"/>
        ... 
    </bean>
</property>
</bean>

You can also change how Ignite behaves if you lose part of a cache with the partition loss policy.