了解siddhi快照概念

Question

我有查询和执行计划，我想要快照，以便我可以恢复它在接收端，并开始执行它。

1. 应向接收方发送何种格式？
2. 如何在接收端恢复？

下面是我从Siddhi存储库获取的一些代码。

 SiddhiManager siddhiManager = new SiddhiManager();
    String query =
            "define stream inStream(meta_roomNumber int,meta_temperature double);" +
                    "from inStream#window(10)[meta_temperature > 50]\n" +
                    "select *" +
                    "insert into outStream;";

    ExecutionPlanRuntime executionPlanRuntime = siddhiManager.createExecutionPlanRuntime(query);

    executionPlanRuntime.start();
    SiddhiContext siddhicontext = new SiddhiContext();

    context.setSiddhiContext(siddhicontext);
    context.setSnapshotService(new SnapshotService(context));
    executionPlanRuntime.snapshot();

Answer 1

您可以使用PersistenceStore来持久化执行计划的状态(快照)，并在以后恢复它。请参考下面的PersistenceTestCase来了解它的用法。即；

    // Create executionPlanRuntime
    ExecutionPlanRuntime executionPlanRuntime = siddhiManager.createExecutionPlanRuntime(executionPlan);

    // Register Callbacks, InputHandlers
    executionPlanRuntime.addCallback("query1", queryCallback);
    stream1 = executionPlanRuntime.getInputHandler("Stream1");

    // Start executionPlanRuntime
    executionPlanRuntime.start();

    // Send events
    stream1.send(new Object[]{"WSO2", 25.6f, 100});
    Thread.sleep(100);
    stream1.send(new Object[]{"GOOG", 47.6f, 100});
    Thread.sleep(100);

    // Persist the state
    executionPlanRuntime.persist();

    // Shutdown the running execution plan
    executionPlanRuntime.shutdown();

    // Create new executionPlanRuntime
    executionPlanRuntime = siddhiManager.createExecutionPlanRuntime(executionPlan);

    // Register Callbacks, InputHandlers
    executionPlanRuntime.addCallback("query1", queryCallback);
    stream1 = executionPlanRuntime.getInputHandler("Stream1");

    // Start executionPlanRuntime
    executionPlanRuntime.start();

    // Restore to previously persisted state
    executionPlanRuntime.restoreLastRevision();