Partition rule "Hash" ( PartitionByLong ) may have a greater interger space than 1024

[Lordess]

Phenonmenon

"Hash" class in rule.xml is redirected to com.actiontech.dble.route.function.PartitionByLong, which uses com.actiontech.dble.route.util.PartitionUtil for routing.

With comments inside, it seems that PartitionUtil wants to limit its sharding space into a [0,1024] interger space.

It will do check when it is initializing:

1. get the dot product of partitionCount array and partitionLength array

dot product :=
{ partitionCount_1, partitionCount_2, ... , partitionCount_n } · { partitionLength_1, partitionLength_2, ... , partitionLength_n }

2. compare the limit and the dot product.

partitionLength = ai[ai.length - 1];
/* other statments */
if (partitionLength > MAX_PARTITION_LENGTH) {
    throw new RuntimeException("error,check your partitionScope definition.MAX(sum(count*length[i]) must be less then 1024 ");
}

But, the limit here is not 1024, but 2880. So, a setting like partitionCount[] = {1} ; paritiontLength[] = {2880} is runnable. Though the case is against the design.

private static final int MAX_PARTITION_LENGTH = 2880;

How to Repeat

Start your dble, which has "Hash" tables, with settings belows, you will find dble works. Though this is against its design goal.

<function name="your_function_name" class="Hash" >
    <property name="partitionCount">1</property>
    <property name="partitionLength">2880</property>
</function>

Fix Suggestion

Change the value of MAX_PARTITION_LENGTH in PartitionUtil with 1024.

private static final int MAX_PARTITION_LENGTH = 1024;

[yanhuqing666]

we will fix the error tip "error,check your partitionScope definition.Sum(count[i]*length[i]) must be less than 2880"