无法加载累积约束，导致 UnsatisfiableConstraint 失败

Question

我一直在尝试在 Accumulo 中处理自定义约束。我通过实施 org.apache.accumulo.core.constraints.Constraint .

创建了约束

但是将其应用于 table 时出现以下错误

Constraint Failures: ConstraintViolationSummary(constrainClass:org.apache.accumulo.tserver.constraints.UnsatisfiableConstraint,violationCode:-1,violationDescription:Failed to load constraints, not accepting mutations., numberOfViolatingMutations:1)

下面是我的代码片段

 package samplepackageforconstraints;

    import java.util.ArrayList;
    import java.util.Collection;
    import java.util.List;

    import org.apache.accumulo.core.constraints.Constraint;
    import org.apache.accumulo.core.data.ColumnUpdate;
    import org.apache.accumulo.core.data.Mutation;

public class LengthConstraintsTest implements Constraint{

    private static final short NOT_ENOUGH_LENGTH = 1;

    @Override
    public List<Short> check(Environment env, Mutation mutation) {
        List<Short> violations = null;
        Collection<ColumnUpdate> updates = mutation.getUpdates();

        for (ColumnUpdate columnUpdate : updates) {

            if (!isLessThanThree(columnUpdate.getValue()))
                violations = addViolation(violations, NOT_ENOUGH_LENGTH);

        }
        return violations;
    }

    @Override
    public String getViolationDescription(short violationCode) {
         switch (violationCode) {
          case NOT_ENOUGH_LENGTH:
            return "Value should be more than 3 character";
        }
        return null;
    }

    private List<Short> addViolation(List<Short> violations, short violation) {
        if (violations == null) {

            violations = new ArrayList<Short>();
            violations.add(violation);
        } else if (!violations.contains(violation)) {

            violations.add(violation);
        }
        return violations;
    }

    private boolean isLessThanThree(byte[] value) {
        if(value.length <3)
        return false;
        else
            return true;
    }
}

我已按照 user manual of accumulo version 1.7 中给出的步骤进行操作还 cloudera 用于加载约束

我使用的版本：accumulo的1.6.0-cdh5.1.4

提前致谢:)

Answer 1

当无法加载约束时，这意味着从 class 路径（通常）加载 class 存在问题，或者（不太可能）class 没有对应Constraint界面

您需要将包含自定义约束的 jar 添加到每个平板电脑服务器的 class路径中。

您可以通过检查引发此异常的节点上的 tserver 日志来进一步调试它。

无法加载累积约束，导致 UnsatisfiableConstraint 失败

Could not load accumulo constraint, getting UnsatisfiableConstraint failure

java

accumulo