`OAL` 基础知识

基本介绍

OAL(Observability Analysis Language) 是一门用来分析流式数据的语言。

因为 OAL 聚焦于度量 Service 、 Service Instance 和 Endpoint 的指标，所以它学习和使用起来非常简单。

OAL 基于 altlr 与 javassist 将 oal 脚本转化为动态生成的类文件。

自从 6.3 版本后， OAL 引擎内置在 OAP 服务器中，可以看做 oal-rt(OAL Runtime) 。 OAL 脚本位置 OAL 配置目录下( /config/oal )，使用者能够更改脚本并重启生效。注意： OAL 脚本仍然是一门编译语言， oal-rt 动态的生成 Java 代码。

如果你配置了环境变量 SW_OAL_ENGINE_DEBUG=Y，能在工作目录下的 oal-rt 目录下找到生成的 Class 文件。

语法

// 声明一个指标

METRICS_NAME = from(SCOPE.(* | [FIELD][,FIELD ...])) // 从某一个SCOPE中获取数据

[.filter(FIELD OP [INT | STRING])] // 可以过滤掉部分数据

.FUNCTION([PARAM][, PARAM ...]) // 使用某个聚合函数将数据聚合

// 禁用一个指标

disable(METRICS_NAME);

语法案例

oap-server/server-bootstrap/src/main/resources/oal/java-agent.oal

// 从ServiceInstanceJVMMemory的used获取数据，只需要 heapStatus 为 true的数据，并取long型的平均值

instance_jvm_memory_heap = from(ServiceInstanceJVMMemory.used).filter(heapStatus == true).longAvg();

org.apache.skywalking.oap.server.core.source.ServiceInstanceJVMMemory

@ScopeDeclaration(id = SERVICE_INSTANCE_JVM_MEMORY, name = "ServiceInstanceJVMMemory", catalog = SERVICE_INSTANCE_CATALOG_NAME)

@ScopeDefaultColumn.VirtualColumnDefinition(fieldName = "entityId", columnName = "entity_id", isID = true, type = String.class)

public class ServiceInstanceJVMMemory extends Source {

    @Override

    public int scope() {

        return DefaultScopeDefine.SERVICE_INSTANCE_JVM_MEMORY;

    }

    @Override

    public String getEntityId() {

        return String.valueOf(id);

    }

    @Getter @Setter

    private String id;

    @Getter @Setter @ScopeDefaultColumn.DefinedByField(columnName = "name", requireDynamicActive = true)

    private String name;

    @Getter @Setter @ScopeDefaultColumn.DefinedByField(columnName = "service_name", requireDynamicActive = true)

    private String serviceName;

    @Getter @Setter @ScopeDefaultColumn.DefinedByField(columnName = "service_id")

    private String serviceId;

    @Getter @Setter

    private boolean heapStatus;

    @Getter @Setter

    private long init;

    @Getter @Setter

    private long max;

    @Getter @Setter

    private long used;

    @Getter @Setter

    private long committed;

}

可供参考的官方文档：Observability Analysis Language

从一个案例开始分析 `OAL` 原理

缺少的类加载信息监控

默认的 APM/Instance 页面，缺少关于 JVM Class 的信息（如下图所示），故这次将相关信息补齐。由这次案例来分析 OAL 的原理。

在 Skywalking-04：扩展Metric监控信息中，讲到了如何在已有 Source 类的情况下，增加一些指标。

这次直接连 Source 类以及 OAL 词法语法关键字都自己定义。

可供参考的官方文档：Source and Scope extension for new metrics

确定增加的指标

通过Java ManagementFactory解析这篇文章，可以确定监控指标为“当前加载类的数量”、“已卸载类的数量”、“一共加载类的数量”三个指标

ClassLoadingMXBean classLoadingMXBean = ManagementFactory.getClassLoadingMXBean();

// 当前加载类的数量

int loadedClassCount = classLoadingMXBean.getLoadedClassCount();

// 已卸载类的数量

long unloadedClassCount = classLoadingMXBean.getUnloadedClassCount();

// 一共加载类的数量

long totalLoadedClassCount = classLoadingMXBean.getTotalLoadedClassCount();

定义 `agent` 与 `oap server` 通讯类

在 apm-protocol/apm-network/src/main/proto/language-agent/JVMMetric.proto 协议文件中增加如下定义。

在 apm-protocol/apm-network 目录下执行 mvn clean package -DskipTests=true 会生成新的相关 Java 类，org.apache.skywalking.apm.network.language.agent.v3.Class 该类就是我们在代码中实际操作的类。

message Class {

  int64 loadedClassCount = 1;

  int64 unloadedClassCount = 3;

  int64 totalLoadedClassCount = 2;

}

message JVMMetric {

    int64 time = 1;

    CPU cpu = 2;

    repeated Memory memory = 3;

    repeated MemoryPool memoryPool = 4;

    repeated GC gc = 5;

    Thread thread = 6;

    // 在JVM指标中添加Class的定义

    Class clazz = 7;

}

收集 `agent` 的信息后，将信息发送至 `oap server`

收集 Class 相关的指标信息

package org.apache.skywalking.apm.agent.core.jvm.clazz;

import org.apache.skywalking.apm.network.language.agent.v3.Class;

import java.lang.management.ClassLoadingMXBean;

import java.lang.management.ManagementFactory;

public enum ClassProvider {

    /**

     * instance

     */

    INSTANCE;

    private final ClassLoadingMXBean classLoadingMXBean;

    ClassProvider() {

        this.classLoadingMXBean = ManagementFactory.getClassLoadingMXBean();

    }

    // 构建class的指标信息

    public Class getClassMetrics() {

        int loadedClassCount = classLoadingMXBean.getLoadedClassCount();

        long unloadedClassCount = classLoadingMXBean.getUnloadedClassCount();

        long totalLoadedClassCount = classLoadingMXBean.getTotalLoadedClassCount();

        return Class.newBuilder().setLoadedClassCount(loadedClassCount)

                .setUnloadedClassCount(unloadedClassCount)

                .setTotalLoadedClassCount(totalLoadedClassCount)

                .build();

    }

}

在 org.apache.skywalking.apm.agent.core.jvm.JVMService#run 方法中，将 class 相关指标设置到 JVM 指标类中

    @Override

    public void run() {

        long currentTimeMillis = System.currentTimeMillis();

        try {

            JVMMetric.Builder jvmBuilder = JVMMetric.newBuilder();

            jvmBuilder.setTime(currentTimeMillis);

            jvmBuilder.setCpu(CPUProvider.INSTANCE.getCpuMetric());

            jvmBuilder.addAllMemory(MemoryProvider.INSTANCE.getMemoryMetricList());

            jvmBuilder.addAllMemoryPool(MemoryPoolProvider.INSTANCE.getMemoryPoolMetricsList());

            jvmBuilder.addAllGc(GCProvider.INSTANCE.getGCList());

            jvmBuilder.setThread(ThreadProvider.INSTANCE.getThreadMetrics());

            // 设置class的指标

            jvmBuilder.setClazz(ClassProvider.INSTANCE.getClassMetrics());

			// 将JVM的指标放在阻塞队列中

            // org.apache.skywalking.apm.agent.core.jvm.JVMMetricsSender#run方法，会将相关信息发送至oap server

            sender.offer(jvmBuilder.build());

        } catch (Exception e) {

            LOGGER.error(e, "Collect JVM info fail.");

        }

    }

创建 `Source` 类

public class DefaultScopeDefine {

    public static final int SERVICE_INSTANCE_JVM_CLASS = 11000;

    /** Catalog of scope, the metrics processor could use this to group all generated metrics by oal rt. */

    public static final String SERVICE_INSTANCE_CATALOG_NAME = "SERVICE_INSTANCE";

}

package org.apache.skywalking.oap.server.core.source;

import lombok.Getter;

import lombok.Setter;

import static org.apache.skywalking.oap.server.core.source.DefaultScopeDefine.SERVICE_INSTANCE_CATALOG_NAME;

import static org.apache.skywalking.oap.server.core.source.DefaultScopeDefine.SERVICE_INSTANCE_JVM_CLASS;

@ScopeDeclaration(id = SERVICE_INSTANCE_JVM_CLASS, name = "ServiceInstanceJVMClass", catalog = SERVICE_INSTANCE_CATALOG_NAME)

@ScopeDefaultColumn.VirtualColumnDefinition(fieldName = "entityId", columnName = "entity_id", isID = true, type = String.class)

public class ServiceInstanceJVMClass extends Source {

    @Override

    public int scope() {

        return SERVICE_INSTANCE_JVM_CLASS;

    }

    @Override

    public String getEntityId() {

        return String.valueOf(id);

    }

    @Getter @Setter

    private String id;

    @Getter @Setter @ScopeDefaultColumn.DefinedByField(columnName = "name", requireDynamicActive = true)

    private String name;

    @Getter @Setter @ScopeDefaultColumn.DefinedByField(columnName = "service_name", requireDynamicActive = true)

    private String serviceName;

    @Getter @Setter @ScopeDefaultColumn.DefinedByField(columnName = "service_id")

    private String serviceId;

    @Getter @Setter

    private long loadedClassCount;

    @Getter @Setter

    private long unloadedClassCount;

    @Getter @Setter

    private long totalLoadedClassCount;

}

将从 `agent` 获取到的信息，发送至 `SourceReceive`

在 org.apache.skywalking.oap.server.analyzer.provider.jvm.JVMSourceDispatcher 进行如下修改

    public void sendMetric(String service, String serviceInstance, JVMMetric metrics) {

        long minuteTimeBucket = TimeBucket.getMinuteTimeBucket(metrics.getTime());

        final String serviceId = IDManager.ServiceID.buildId(service, NodeType.Normal);

        final String serviceInstanceId = IDManager.ServiceInstanceID.buildId(serviceId, serviceInstance);

        this.sendToCpuMetricProcess(

            service, serviceId, serviceInstance, serviceInstanceId, minuteTimeBucket, metrics.getCpu());

        this.sendToMemoryMetricProcess(

            service, serviceId, serviceInstance, serviceInstanceId, minuteTimeBucket, metrics.getMemoryList());

        this.sendToMemoryPoolMetricProcess(

            service, serviceId, serviceInstance, serviceInstanceId, minuteTimeBucket, metrics.getMemoryPoolList());

        this.sendToGCMetricProcess(

            service, serviceId, serviceInstance, serviceInstanceId, minuteTimeBucket, metrics.getGcList());

        this.sendToThreadMetricProcess(

                service, serviceId, serviceInstance, serviceInstanceId, minuteTimeBucket, metrics.getThread());

        // class指标处理

        this.sendToClassMetricProcess(

                service, serviceId, serviceInstance, serviceInstanceId, minuteTimeBucket, metrics.getClazz());

    }

    private void sendToClassMetricProcess(String service,

            String serviceId,

            String serviceInstance,

            String serviceInstanceId,

            long timeBucket,

            Class clazz) {

        // 拼装Source对象

        ServiceInstanceJVMClass serviceInstanceJVMClass = new ServiceInstanceJVMClass();

        serviceInstanceJVMClass.setId(serviceInstanceId);

        serviceInstanceJVMClass.setName(serviceInstance);

        serviceInstanceJVMClass.setServiceId(serviceId);

        serviceInstanceJVMClass.setServiceName(service);

        serviceInstanceJVMClass.setLoadedClassCount(clazz.getLoadedClassCount());

        serviceInstanceJVMClass.setUnloadedClassCount(clazz.getUnloadedClassCount());

        serviceInstanceJVMClass.setTotalLoadedClassCount(clazz.getTotalLoadedClassCount());

        serviceInstanceJVMClass.setTimeBucket(timeBucket);

        // 将Source对象发送至SourceReceive进行处理

        sourceReceiver.receive(serviceInstanceJVMClass);

    }

在 `OAL` 词法定义和语法定义中加入 `Source` 相关信息

在 oap-server/oal-grammar/src/main/antlr4/org/apache/skywalking/oal/rt/grammar/OALLexer.g4 定义 Class 关键字

// Keywords

FROM: 'from';

FILTER: 'filter';

DISABLE: 'disable';

SRC_ALL: 'All';

SRC_SERVICE: 'Service';

SRC_SERVICE_INSTANCE: 'ServiceInstance';

SRC_ENDPOINT: 'Endpoint';

SRC_SERVICE_RELATION: 'ServiceRelation';

SRC_SERVICE_INSTANCE_RELATION: 'ServiceInstanceRelation';

SRC_ENDPOINT_RELATION: 'EndpointRelation';

SRC_SERVICE_INSTANCE_JVM_CPU: 'ServiceInstanceJVMCPU';

SRC_SERVICE_INSTANCE_JVM_MEMORY: 'ServiceInstanceJVMMemory';

SRC_SERVICE_INSTANCE_JVM_MEMORY_POOL: 'ServiceInstanceJVMMemoryPool';

SRC_SERVICE_INSTANCE_JVM_GC: 'ServiceInstanceJVMGC';

SRC_SERVICE_INSTANCE_JVM_THREAD: 'ServiceInstanceJVMThread';

SRC_SERVICE_INSTANCE_JVM_CLASS:'ServiceInstanceJVMClass'; // 在OAL词法定义中添加Class的关键字

SRC_DATABASE_ACCESS: 'DatabaseAccess';

SRC_SERVICE_INSTANCE_CLR_CPU: 'ServiceInstanceCLRCPU';

SRC_SERVICE_INSTANCE_CLR_GC: 'ServiceInstanceCLRGC';

SRC_SERVICE_INSTANCE_CLR_THREAD: 'ServiceInstanceCLRThread';

SRC_ENVOY_INSTANCE_METRIC: 'EnvoyInstanceMetric';

在 oap-server/oal-grammar/src/main/antlr4/org/apache/skywalking/oal/rt/grammar/OALParser.g4 添加 Class 关键字

source

    : SRC_ALL | SRC_SERVICE | SRC_DATABASE_ACCESS | SRC_SERVICE_INSTANCE | SRC_ENDPOINT |

      SRC_SERVICE_RELATION | SRC_SERVICE_INSTANCE_RELATION | SRC_ENDPOINT_RELATION |

      SRC_SERVICE_INSTANCE_JVM_CPU | SRC_SERVICE_INSTANCE_JVM_MEMORY | SRC_SERVICE_INSTANCE_JVM_MEMORY_POOL |

      SRC_SERVICE_INSTANCE_JVM_GC | SRC_SERVICE_INSTANCE_JVM_THREAD | SRC_SERVICE_INSTANCE_JVM_CLASS |// 在OAL语法定义中添加词法定义中定义的关键字

      SRC_SERVICE_INSTANCE_CLR_CPU | SRC_SERVICE_INSTANCE_CLR_GC | SRC_SERVICE_INSTANCE_CLR_THREAD |

      SRC_ENVOY_INSTANCE_METRIC |

      SRC_BROWSER_APP_PERF | SRC_BROWSER_APP_PAGE_PERF | SRC_BROWSER_APP_SINGLE_VERSION_PERF |

      SRC_BROWSER_APP_TRAFFIC | SRC_BROWSER_APP_PAGE_TRAFFIC | SRC_BROWSER_APP_SINGLE_VERSION_TRAFFIC

    ;

在 oap-server/oal-grammar 目录下执行 mvn clean package -DskipTests=true 会生成新的相关 Java 类

定义 `OAL` 指标

在 oap-server/server-bootstrap/src/main/resources/oal/java-agent.oal 中添加基于 OAL 语法的 Class 相关指标定义

// 当前加载类的数量

instance_jvm_class_loaded_class_count = from(ServiceInstanceJVMClass.loadedClassCount).longAvg();

// 已卸载类的数量

instance_jvm_class_unloaded_class_count = from(ServiceInstanceJVMClass.unloadedClassCount).longAvg();

// 一共加载类的数量

instance_jvm_class_total_loaded_class_count = from(ServiceInstanceJVMClass.totalLoadedClassCount).longAvg();

配置 `UI` 面板

将如下界面配置导入 APM 面板中

{

  "name": "Instance",

  "children": [{

      "width": "3",

      "title": "Service Instance Load",

      "height": "250",

      "entityType": "ServiceInstance",

      "independentSelector": false,

      "metricType": "REGULAR_VALUE",

      "metricName": "service_instance_cpm",

      "queryMetricType": "readMetricsValues",

      "chartType": "ChartLine",

      "unit": "CPM - calls per minute"

    },

    {

      "width": 3,

      "title": "Service Instance Throughput",

      "height": "250",

      "entityType": "ServiceInstance",

      "independentSelector": false,

      "metricType": "REGULAR_VALUE",

      "metricName": "service_instance_throughput_received,service_instance_throughput_sent",

      "queryMetricType": "readMetricsValues",

      "chartType": "ChartLine",

      "unit": "Bytes"

    },

    {

      "width": "3",

      "title": "Service Instance Successful Rate",

      "height": "250",

      "entityType": "ServiceInstance",

      "independentSelector": false,

      "metricType": "REGULAR_VALUE",

      "metricName": "service_instance_sla",

      "queryMetricType": "readMetricsValues",

      "chartType": "ChartLine",

      "unit": "%",

      "aggregation": "/",

      "aggregationNum": "100"

    },

    {

      "width": "3",

      "title": "Service Instance Latency",

      "height": "250",

      "entityType": "ServiceInstance",

      "independentSelector": false,

      "metricType": "REGULAR_VALUE",

      "metricName": "service_instance_resp_time",

      "queryMetricType": "readMetricsValues",

      "chartType": "ChartLine",

      "unit": "ms"

    },

    {

      "width": 3,

      "title": "JVM CPU (Java Service)",

      "height": "250",

      "entityType": "ServiceInstance",

      "independentSelector": false,

      "metricType": "REGULAR_VALUE",

      "metricName": "instance_jvm_cpu",

      "queryMetricType": "readMetricsValues",

      "chartType": "ChartLine",

      "unit": "%",

      "aggregation": "+",

      "aggregationNum": ""

    },

    {

      "width": 3,

      "title": "JVM Memory (Java Service)",

      "height": "250",

      "entityType": "ServiceInstance",

      "independentSelector": false,

      "metricType": "REGULAR_VALUE",

      "metricName": "instance_jvm_memory_heap, instance_jvm_memory_heap_max,instance_jvm_memory_noheap, instance_jvm_memory_noheap_max",

      "queryMetricType": "readMetricsValues",

      "chartType": "ChartLine",

      "unit": "MB",

      "aggregation": "/",

      "aggregationNum": "1048576"

    },

    {

      "width": 3,

      "title": "JVM GC Time",

      "height": "250",

      "entityType": "ServiceInstance",

      "independentSelector": false,

      "metricType": "REGULAR_VALUE",

      "metricName": "instance_jvm_young_gc_time, instance_jvm_old_gc_time",

      "queryMetricType": "readMetricsValues",

      "chartType": "ChartLine",

      "unit": "ms"

    },

    {

      "width": 3,

      "title": "JVM GC Count",

      "height": "250",

      "entityType": "ServiceInstance",

      "independentSelector": false,

      "metricType": "REGULAR_VALUE",

      "queryMetricType": "readMetricsValues",

      "chartType": "ChartBar",

      "metricName": "instance_jvm_young_gc_count, instance_jvm_old_gc_count"

    },

    {

      "width": 3,

      "title": "JVM Thread Count (Java Service)",

      "height": "250",

      "entityType": "ServiceInstance",

      "independentSelector": false,

      "metricType": "REGULAR_VALUE",

      "queryMetricType": "readMetricsValues",

      "chartType": "ChartLine",

      "metricName": "instance_jvm_thread_live_count, instance_jvm_thread_daemon_count, instance_jvm_thread_peak_count,instance_jvm_thread_deadlocked,instance_jvm_thread_monitor_deadlocked"

    },

    {

      "width": 3,

      "title": "JVM Thread State Count (Java Service)",

      "height": "250",

      "entityType": "ServiceInstance",

      "independentSelector": false,

      "metricType": "REGULAR_VALUE",

      "metricName": "instance_jvm_thread_new_thread_count,instance_jvm_thread_runnable_thread_count,instance_jvm_thread_blocked_thread_count,instance_jvm_thread_wait_thread_count,instance_jvm_thread_time_wait_thread_count,instance_jvm_thread_terminated_thread_count",

      "queryMetricType": "readMetricsValues",

      "chartType": "ChartBar"

    },

    {

      "width": 3,

      "title": "JVM Class Count (Java Service)",

      "height": "250",

      "entityType": "ServiceInstance",

      "independentSelector": false,

      "metricType": "REGULAR_VALUE",

      "metricName": "instance_jvm_class_loaded_class_count,instance_jvm_class_unloaded_class_count,instance_jvm_class_total_loaded_class_count",

      "queryMetricType": "readMetricsValues",

      "chartType": "ChartArea"

    },

    {

      "width": 3,

      "title": "CLR CPU  (.NET Service)",

      "height": "250",

      "entityType": "ServiceInstance",

      "independentSelector": false,

      "metricType": "REGULAR_VALUE",

      "metricName": "instance_clr_cpu",

      "queryMetricType": "readMetricsValues",

      "chartType": "ChartLine",

      "unit": "%"

    },

    {

      "width": 3,

      "title": "CLR GC (.NET Service)",

      "height": "250",

      "entityType": "ServiceInstance",

      "independentSelector": false,

      "metricType": "REGULAR_VALUE",

      "metricName": "instance_clr_gen0_collect_count, instance_clr_gen1_collect_count, instance_clr_gen2_collect_count",

      "queryMetricType": "readMetricsValues",

      "chartType": "ChartBar"

    },

    {

      "width": 3,

      "title": "CLR Heap Memory (.NET Service)",

      "height": "250",

      "entityType": "ServiceInstance",

      "independentSelector": false,

      "metricType": "REGULAR_VALUE",

      "metricName": "instance_clr_heap_memory",

      "queryMetricType": "readMetricsValues",

      "chartType": "ChartLine",

      "unit": "MB",

      "aggregation": "/",

      "aggregationNum": "1048576"

    },

    {

      "width": 3,

      "title": "CLR Thread (.NET Service)",

      "height": "250",

      "entityType": "ServiceInstance",

      "independentSelector": false,

      "metricType": "REGULAR_VALUE",

      "queryMetricType": "readMetricsValues",

      "chartType": "ChartLine",

      "metricName": "instance_clr_available_completion_port_threads,instance_clr_available_worker_threads,instance_clr_max_completion_port_threads,instance_clr_max_worker_threads"

    }

  ]

}

结果校验

可以看到导入的界面中，已经有 Class 相关指标了

代码贡献

参考文档

分享并记录所学所见

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Skywalking-06：OAL基础

OAL 基础知识

基本介绍

语法

语法案例

从一个案例开始分析 OAL 原理

缺少的类加载信息监控

确定增加的指标

定义 agent 与 oap server 通讯类

收集 agent 的信息后，将信息发送至 oap server

创建 Source 类

将从 agent 获取到的信息，发送至 SourceReceive

在 OAL 词法定义和语法定义中加入 Source 相关信息

定义 OAL 指标

配置 UI 面板