MyCATApache/Mycat-Server · critical · RuntimeException

error,check your partitionScope definition.

Error message

error,check your partitionScope definition.

What it means

PartitionUtil builds its internal cumulative partition boundary array from per-partition length arrays and validates the total equals PARTITION_LENGTH (the full hash ring, e.g. 1024). If the configured partition lengths do not sum to the full range, the constructor throws this RuntimeException immediately. It is a fail-fast guard against a misconfigured partition scope in partition-charset files or count/length arrays.

Solutions

  1. Fix the partition rule config so partitionCount[i] * partitionLength[i] values sum exactly to 1024 (PARTITION_LENGTH)
  2. If using a partition pattern file, make each region's start contiguous with the previous end with no gaps or overlaps (e.g. lines 0-1023 covering the full range once)
  3. Verify the schema.xml rule function's count/length attributes match the intended total, e.g. <function name="..." count="2" length="512"/> sums to 1024

Example fix

// before (schema.xml rule config)
<property name="count">3</property>
<property name="length">400</property>  <!-- 3*400=1200 != 1024 -->
// after
<property name="count">2</property>
<property name="length">512</property>  <!-- 2*512=1024 -->
Defensive patterns

Strategy: validation

Validate before calling

// validate before constructing PartitionUtil
int total = 0;
for (int i = 0; i < partitionCount.length; i++) { total += partitionCount[i] * partitionLength[i]; }
if (total != 1024) throw new IllegalStateException("partition lengths sum to " + total + ", expected 1024");

Try / catch

try { PartitionUtil pu = new PartitionUtil(count, length); } catch (RuntimeException e) { /* log config error, fail startup */ }

Prevention

When it happens

Trigger: Constructing PartitionUtil where the sum of all partition lengths (partitionCount[i] * partitionLength[i], or values from a partition pattern file) does not equal PARTITION_LENGTH (1024). Caused by inconsistent partitionCount/partitionLength values passed in or a partition-range file whose ranges overlap or leave gaps.

Common situations: Editing partition-range pattern files (e.g. for hash-int or long range rules) by hand and leaving gaps or overlaps between regions; copying a rule config for a different modulo (e.g. 1024 vs 3600) without updating counts; sum of lengths accidentally doubled by overlapping file entries.

Understand the failure class

Background: "Invalid value" and "allowed values are" config errors: what your library rejected and how to fix it — this error's family across 41 libraries.

Related errors

AI-assisted analysis of MyCATApache/Mycat-Server@65f8d8beb7 (2026-09-11). Data as JSON: /api/errors/24a6690f0201a245. Report an issue: GitHub.

Appendix: source

Thrown at src/main/java/io/mycat/route/util/PartitionUtil.java:69

     */
    public PartitionUtil(int[] count, int[] length) {
        if (count == null || length == null || (count.length != length.length)) {
            throw new RuntimeException("error,check your scope & scopeLength definition.");
        }
        int segmentLength = 0;
        for (int i = 0; i < count.length; i++) {
            segmentLength += count[i];
        }
        int[] ai = new int[segmentLength + 1];

        int index = 0;
        for (int i = 0; i < count.length; i++) {
            for (int j = 0; j < count[i]; j++) {
                ai[++index] = ai[index - 1] + length[i];
            }
        }
        if (ai[ai.length - 1] != PARTITION_LENGTH) {
            throw new RuntimeException("error,check your partitionScope definition.");
        }

        // 数据映射操作
        for (int i = 1; i < ai.length; i++) {
            for (int j = ai[i - 1]; j < ai[i]; j++) {
                segment[j] = (i - 1);
            }
        }
    }

    public int partition(long hash) {
        return segment[(int) (hash & AND_VALUE)];
    }

    public int partition(String key, int start, int end) {
        return partition(StringUtil.hash(key, start, end));
    }

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