聊聊skywalking的mysql-plugin

序

本文主要研究一下skywalking的mysql-plugin

skywalking-plugin.def

skywalking-6.6.0/apm-sniffer/apm-sdk-plugin/mysql-8.x-plugin/src/main/resources/skywalking-plugin.def

mysql-8.x=org.apache.skywalking.apm.plugin.jdbc.mysql.v8.define.ConnectionImplCreateInstrumentation
mysql-8.x=org.apache.skywalking.apm.plugin.jdbc.mysql.v8.define.ConnectionInstrumentation
mysql-8.x=org.apache.skywalking.apm.plugin.jdbc.mysql.v8.define.CallableInstrumentation
mysql-8.x=org.apache.skywalking.apm.plugin.jdbc.mysql.v8.define.PreparedStatementInstrumentation
mysql-8.x=org.apache.skywalking.apm.plugin.jdbc.mysql.v8.define.StatementInstrumentation
mysql-8.x=org.apache.skywalking.apm.plugin.jdbc.mysql.v8.define.PreparedStatementSetterInstrumentation
mysql-8.x=org.apache.skywalking.apm.plugin.jdbc.mysql.v8.define.PreparedStatementNullSetterInstrumentation
mysql-8.x=org.apache.skywalking.apm.plugin.jdbc.mysql.v8.define.PreparedStatementIgnoredSetterInstrumentation

• skywalking的mysql-plugin提供了ConnectionImplCreateInstrumentation、ConnectionInstrumentation、CallableInstrumentation、PreparedStatementInstrumentation、StatementInstrumentation、PreparedStatementSetterInstrumentation、PreparedStatementNullSetterInstrumentation、PreparedStatementIgnoredSetterInstrumentation这几个增强

AbstractMysqlInstrumentation

skywalking-6.6.0/apm-sniffer/apm-sdk-plugin/mysql-8.x-plugin/src/main/java/org/apache/skywalking/apm/plugin/jdbc/mysql/v8/define/AbstractMysqlInstrumentation.java

public abstract class AbstractMysqlInstrumentation extends ClassEnhancePluginDefine {

    @Override
    public ConstructorInterceptPoint[] getConstructorsInterceptPoints() {
        return null;
    }
    @Override
    public StaticMethodsInterceptPoint[] getStaticMethodsInterceptPoints() {
        return null;
    }

    @Override
    public InstanceMethodsInterceptPoint[] getInstanceMethodsInterceptPoints() {
        return null;
    }


    @Override
    protected String[] witnessClasses() {
        return new String[]{Constants.WITNESS_MYSQL_8X_CLASS};
    }
}

• AbstractMysqlInstrumentation继承了ClassEnhancePluginDefine，其witnessClasses返回的是com.mysql.cj.interceptors.QueryInterceptor

ConnectionImplCreateInstrumentation

skywalking-6.6.0/apm-sniffer/apm-sdk-plugin/mysql-8.x-plugin/src/main/java/org/apache/skywalking/apm/plugin/jdbc/mysql/v8/define/ConnectionImplCreateInstrumentation.java

public class ConnectionImplCreateInstrumentation extends AbstractMysqlInstrumentation {

    private static final String JDBC_ENHANCE_CLASS = "com.mysql.cj.jdbc.ConnectionImpl";

    private static final String CONNECT_METHOD = "getInstance";


    @Override
    public StaticMethodsInterceptPoint[] getStaticMethodsInterceptPoints() {
        return new StaticMethodsInterceptPoint[] {
            new StaticMethodsInterceptPoint() {
                @Override
                public ElementMatcher<MethodDescription> getMethodsMatcher() {
                    return named(CONNECT_METHOD);
                }

                @Override
                public String getMethodsInterceptor() {
                    return "org.apache.skywalking.apm.plugin.jdbc.mysql.v8.ConnectionCreateInterceptor";
                }

                @Override
                public boolean isOverrideArgs() {
                    return false;
                }
            }
        };
    }

    @Override
    protected ClassMatch enhanceClass() {
        return byName(JDBC_ENHANCE_CLASS);
    }
}

• ConnectionImplCreateInstrumentation继承了AbstractMysqlInstrumentation；它使用org.apache.skywalking.apm.plugin.jdbc.mysql.v8.ConnectionCreateInterceptor增强了com.mysql.cj.jdbc.ConnectionImpl的getInstance方法

ConnectionCreateInterceptor

skywalking-6.6.0/apm-sniffer/apm-sdk-plugin/mysql-8.x-plugin/src/main/java/org/apache/skywalking/apm/plugin/jdbc/mysql/v8/ConnectionCreateInterceptor.java

public class ConnectionCreateInterceptor implements StaticMethodsAroundInterceptor {


    @Override
    public void beforeMethod(Class clazz, Method method, Object[] allArguments, Class<?>[] parameterTypes, MethodInterceptResult result) {

    }

    @Override
    public Object afterMethod(Class clazz, Method method, Object[] allArguments, Class<?>[] parameterTypes, Object ret) {
        if (ret instanceof EnhancedInstance) {
            final HostInfo hostInfo = (HostInfo) allArguments[0];
            ConnectionInfo connectionInfo = URLParser.parser(hostInfo.getDatabaseUrl());
            ((EnhancedInstance) ret).setSkyWalkingDynamicField(connectionInfo);
        }
        return ret;
    }

    @Override
    public void handleMethodException(Class clazz, Method method, Object[] allArguments, Class<?>[] parameterTypes, Throwable t) {

    }
}

• ConnectionCreateInterceptor实现了StaticMethodsAroundInterceptor接口，其afterMethod方法提取hostInfo解析为connectionInfo然后设置给ret的skyWalkingDynamicField

ConnectionInstrumentation

skywalking-6.6.0/apm-sniffer/apm-sdk-plugin/mysql-8.x-plugin/src/main/java/org/apache/skywalking/apm/plugin/jdbc/mysql/v8/define/ConnectionInstrumentation.java

public class ConnectionInstrumentation extends AbstractMysqlInstrumentation {

    @Override public ConstructorInterceptPoint[] getConstructorsInterceptPoints() {
        return new ConstructorInterceptPoint[0];
    }

    @Override public InstanceMethodsInterceptPoint[] getInstanceMethodsInterceptPoints() {
        return new InstanceMethodsInterceptPoint[] {
            new InstanceMethodsInterceptPoint() {
                @Override public ElementMatcher<MethodDescription> getMethodsMatcher() {
                    return named(org.apache.skywalking.apm.plugin.jdbc.define.Constants.PREPARE_STATEMENT_METHOD_NAME);
                }

                @Override public String getMethodsInterceptor() {
                    return org.apache.skywalking.apm.plugin.jdbc.mysql.Constants.CREATE_PREPARED_STATEMENT_INTERCEPTOR;
                }

                @Override public boolean isOverrideArgs() {
                    return false;
                }
            },
            new InstanceMethodsInterceptPoint() {
                @Override public ElementMatcher<MethodDescription> getMethodsMatcher() {
                    return named(org.apache.skywalking.apm.plugin.jdbc.define.Constants.PREPARE_CALL_METHOD_NAME);
                }

                @Override public String getMethodsInterceptor() {
                    return org.apache.skywalking.apm.plugin.jdbc.mysql.Constants.CREATE_CALLABLE_STATEMENT_INTERCEPTOR;
                }

                @Override public boolean isOverrideArgs() {
                    return false;
                }
            },
            new InstanceMethodsInterceptPoint() {
                @Override public ElementMatcher<MethodDescription> getMethodsMatcher() {
                    return named(org.apache.skywalking.apm.plugin.jdbc.define.Constants.CREATE_STATEMENT_METHOD_NAME).and(takesArguments(2));
                }

                @Override public String getMethodsInterceptor() {
                    return org.apache.skywalking.apm.plugin.jdbc.mysql.Constants.CREATE_STATEMENT_INTERCEPTOR;
                }

                @Override public boolean isOverrideArgs() {
                    return false;
                }
            },
            new InstanceMethodsInterceptPoint() {
                @Override public ElementMatcher<MethodDescription> getMethodsMatcher() {
                    return named(org.apache.skywalking.apm.plugin.jdbc.define.Constants.COMMIT_METHOD_NAME).or(named(org.apache.skywalking.apm.plugin.jdbc.define.Constants.ROLLBACK_METHOD_NAME)).or(named(org.apache.skywalking.apm.plugin.jdbc.define.Constants.CLOSE_METHOD_NAME)).or(named(org.apache.skywalking.apm.plugin.jdbc.define.Constants.RELEASE_SAVE_POINT_METHOD_NAME));
                }

                @Override public String getMethodsInterceptor() {
                    return org.apache.skywalking.apm.plugin.jdbc.define.Constants.SERVICE_METHOD_INTERCEPT_CLASS;
                }

                @Override public boolean isOverrideArgs() {
                    return false;
                }
            },
            new InstanceMethodsInterceptPoint() {
                @Override public ElementMatcher<MethodDescription> getMethodsMatcher() {
                    return named("setCatalog");
                }

                @Override public String getMethodsInterceptor() {
                    return org.apache.skywalking.apm.plugin.jdbc.mysql.Constants.SET_CATALOG_INTERCEPTOR;
                }

                @Override public boolean isOverrideArgs() {
                    return false;
                }
            }
        };

    }


    @Override protected ClassMatch enhanceClass() {
        return byName("com.mysql.cj.jdbc.ConnectionImpl");
    }

}

• ConnectionInstrumentation继承了AbstractMysqlInstrumentation，它增强的是com.mysql.cj.jdbc.ConnectionImpl类；它使用org.apache.skywalking.apm.plugin.jdbc.mysql.CreatePreparedStatementInterceptor增强其prepareStatement方法；它使用org.apache.skywalking.apm.plugin.jdbc.mysql.CreateCallableStatementInterceptor增强其prepareCall方法；它使用org.apache.skywalking.apm.plugin.jdbc.mysql.CreateStatementInterceptor增强其createStatement方法；它使用org.apache.skywalking.apm.plugin.jdbc.ConnectionServiceMethodInterceptor增强其commit、rollback、close、releaseSavepoint方法；它使用org.apache.skywalking.apm.plugin.jdbc.mysql.SetCatalogInterceptor增强其setCatalog方法

CreatePreparedStatementInterceptor

skywalking-6.6.0/apm-sniffer/apm-sdk-plugin/mysql-common/src/main/java/org/apache/skywalking/apm/plugin/jdbc/mysql/CreatePreparedStatementInterceptor.java

public class CreatePreparedStatementInterceptor implements InstanceMethodsAroundInterceptor {
    @Override
    public void beforeMethod(EnhancedInstance objInst, Method method, Object[] allArguments, Class<?>[] argumentsTypes,
        MethodInterceptResult result) throws Throwable {
    }

    @Override
    public Object afterMethod(EnhancedInstance objInst, Method method, Object[] allArguments, Class<?>[] argumentsTypes,
        Object ret) throws Throwable {
        if (ret instanceof EnhancedInstance) {
            ((EnhancedInstance)ret).setSkyWalkingDynamicField(new StatementEnhanceInfos((ConnectionInfo)objInst.getSkyWalkingDynamicField(), (String)allArguments[0], "PreparedStatement"));
        }
        return ret;
    }

    @Override public void handleMethodException(EnhancedInstance objInst, Method method, Object[] allArguments,
        Class<?>[] argumentsTypes, Throwable t) {

    }
}

• CreatePreparedStatementInterceptor实现了InstanceMethodsAroundInterceptor接口，其afterMethod方法会将StatementEnhanceInfos设置给ret的skyWalkingDynamicField

CreateCallableStatementInterceptor

skywalking-6.6.0/apm-sniffer/apm-sdk-plugin/mysql-common/src/main/java/org/apache/skywalking/apm/plugin/jdbc/mysql/CreateCallableStatementInterceptor.java

public class CreateCallableStatementInterceptor implements InstanceMethodsAroundInterceptor {
    @Override
    public void beforeMethod(EnhancedInstance objInst, Method method, Object[] allArguments, Class<?>[] argumentsTypes,
        MethodInterceptResult result) throws Throwable {

    }

    @Override
    public Object afterMethod(EnhancedInstance objInst, Method method, Object[] allArguments, Class<?>[] argumentsTypes,
        Object ret) throws Throwable {
        if (ret instanceof EnhancedInstance) {
            ((EnhancedInstance)ret).setSkyWalkingDynamicField(new StatementEnhanceInfos((ConnectionInfo)objInst.getSkyWalkingDynamicField(), (String)allArguments[0], "CallableStatement"));
        }
        return ret;
    }

    @Override public void handleMethodException(EnhancedInstance objInst, Method method, Object[] allArguments,
        Class<?>[] argumentsTypes, Throwable t) {

    }
}

• CreateCallableStatementInterceptor实现了InstanceMethodsAroundInterceptor接口，其afterMethod方法将StatementEnhanceInfos设置给ret的skyWalkingDynamicField

CreateStatementInterceptor

skywalking-6.6.0/apm-sniffer/apm-sdk-plugin/mysql-common/src/main/java/org/apache/skywalking/apm/plugin/jdbc/mysql/CreateStatementInterceptor.java

public class CreateStatementInterceptor implements InstanceMethodsAroundInterceptor {
    @Override
    public void beforeMethod(EnhancedInstance objInst, Method method, Object[] allArguments, Class<?>[] argumentsTypes,
        MethodInterceptResult result) throws Throwable {

    }

    @Override
    public Object afterMethod(EnhancedInstance objInst, Method method, Object[] allArguments, Class<?>[] argumentsTypes,
        Object ret) throws Throwable {
        if (ret instanceof EnhancedInstance) {
            ((EnhancedInstance)ret).setSkyWalkingDynamicField(new StatementEnhanceInfos((ConnectionInfo)objInst.getSkyWalkingDynamicField(), "", "Statement"));
        }
        return ret;
    }

    @Override public void handleMethodException(EnhancedInstance objInst, Method method, Object[] allArguments,
        Class<?>[] argumentsTypes, Throwable t) {

    }
}

• CreateStatementInterceptor实现了InstanceMethodsAroundInterceptor接口，其afterMethod方法将StatementEnhanceInfos设置给ret的skyWalkingDynamicField

ConnectionServiceMethodInterceptor

skywalking-6.6.0/apm-sniffer/apm-sdk-plugin/jdbc-commons/src/main/java/org/apache/skywalking/apm/plugin/jdbc/ConnectionServiceMethodInterceptor.java

public class ConnectionServiceMethodInterceptor implements InstanceMethodsAroundInterceptor {

    @Override
    public final void beforeMethod(EnhancedInstance objInst, Method method, Object[] allArguments,
        Class<?>[] argumentsTypes,
        MethodInterceptResult result) throws Throwable {
        ConnectionInfo connectInfo = (ConnectionInfo)objInst.getSkyWalkingDynamicField();
        if (connectInfo != null) {
            AbstractSpan span = ContextManager.createExitSpan(connectInfo.getDBType() + "/JDBI/Connection/" + method.getName(), connectInfo.getDatabasePeer());
            Tags.DB_TYPE.set(span, "sql");
            Tags.DB_INSTANCE.set(span, connectInfo.getDatabaseName());
            Tags.DB_STATEMENT.set(span, "");
            span.setComponent(connectInfo.getComponent());
            SpanLayer.asDB(span);
        }
    }

    @Override
    public final Object afterMethod(EnhancedInstance objInst, Method method, Object[] allArguments,
        Class<?>[] argumentsTypes,
        Object ret) throws Throwable {
        ConnectionInfo connectInfo = (ConnectionInfo)objInst.getSkyWalkingDynamicField();
        if (connectInfo != null) {
            ContextManager.stopSpan();
        }
        return ret;
    }

    @Override public final void handleMethodException(EnhancedInstance objInst, Method method, Object[] allArguments,
        Class<?>[] argumentsTypes, Throwable t) {
        ContextManager.activeSpan().errorOccurred().log(t);
    }

}

• ConnectionServiceMethodInterceptor实现了InstanceMethodsAroundInterceptor接口，其beforeMethod方法设置DB_TYPE、DB_INSTANCE、DB_STATEMENT；其afterMethod方法在connectInfo不为null时执行ContextManager.stopSpan()；其handleMethodException方法执行ContextManager.activeSpan().errorOccurred().log(t)

SetCatalogInterceptor

skywalking-6.6.0/apm-sniffer/apm-sdk-plugin/mysql-common/src/main/java/org/apache/skywalking/apm/plugin/jdbc/mysql/SetCatalogInterceptor.java

public class SetCatalogInterceptor implements InstanceMethodsAroundInterceptor {
    @Override
    public void beforeMethod(EnhancedInstance objInst, Method method, Object[] allArguments, Class<?>[] argumentsTypes,
        MethodInterceptResult result) throws Throwable {
        Object dynamicField = objInst.getSkyWalkingDynamicField();
        if (dynamicField instanceof ConnectionInfo) {
            ((ConnectionInfo)dynamicField).setDatabaseName(String.valueOf(allArguments[0]));
        }
    }

    @Override
    public Object afterMethod(EnhancedInstance objInst, Method method, Object[] allArguments, Class<?>[] argumentsTypes,
        Object ret) throws Throwable {
        return ret;
    }

    @Override public void handleMethodException(EnhancedInstance objInst, Method method, Object[] allArguments,
        Class<?>[] argumentsTypes, Throwable t) {
    }
}

• SetCatalogInterceptor实现了InstanceMethodsAroundInterceptor接口，其beforeMethod方法给类型为ConnectionInfo的dynamicField设置databaseName

CallableInstrumentation

skywalking-6.6.0/apm-sniffer/apm-sdk-plugin/mysql-8.x-plugin/src/main/java/org/apache/skywalking/apm/plugin/jdbc/mysql/v8/define/CallableInstrumentation.java

public class CallableInstrumentation extends AbstractMysqlInstrumentation {
    private static final String ENHANCE_CLASS = "com.mysql.cj.jdbc.CallableStatement";
    private static final String SERVICE_METHOD_INTERCEPTOR = org.apache.skywalking.apm.plugin.jdbc.mysql.Constants.PREPARED_STATEMENT_EXECUTE_METHODS_INTERCEPTOR;

    @Override public ConstructorInterceptPoint[] getConstructorsInterceptPoints() {
        return new ConstructorInterceptPoint[0];
    }

    @Override public InstanceMethodsInterceptPoint[] getInstanceMethodsInterceptPoints() {
        return new InstanceMethodsInterceptPoint[] {
            new InstanceMethodsInterceptPoint() {
                @Override public ElementMatcher<MethodDescription> getMethodsMatcher() {
                    return named("execute")
                        .or(named("executeQuery"))
                        .or(named("executeUpdate"));
                }

                @Override public String getMethodsInterceptor() {
                    return SERVICE_METHOD_INTERCEPTOR;
                }

                @Override public boolean isOverrideArgs() {
                    return false;
                }
            }
        };
    }

    @Override protected ClassMatch enhanceClass() {
        return byName(ENHANCE_CLASS);
    }

}

• CallableInstrumentation继承了AbstractMysqlInstrumentation，它使用org.apache.skywalking.apm.plugin.jdbc.mysql.PreparedStatementExecuteMethodsInterceptor增强了com.mysql.cj.jdbc.CallableStatement的execute、executeQuery、executeUpdate方法

PreparedStatementExecuteMethodsInterceptor

skywalking-6.6.0/apm-sniffer/apm-sdk-plugin/mysql-common/src/main/java/org/apache/skywalking/apm/plugin/jdbc/mysql/PreparedStatementExecuteMethodsInterceptor.java

public class PreparedStatementExecuteMethodsInterceptor implements InstanceMethodsAroundInterceptor {

    @Override
    public final void beforeMethod(EnhancedInstance objInst, Method method, Object[] allArguments,
        Class<?>[] argumentsTypes,
        MethodInterceptResult result) throws Throwable {
        StatementEnhanceInfos cacheObject = (StatementEnhanceInfos)objInst.getSkyWalkingDynamicField();
        ConnectionInfo connectInfo = cacheObject.getConnectionInfo();
        /**
         * For avoid NPE. In this particular case, Execute sql inside the {@link com.mysql.jdbc.ConnectionImpl} constructor,
         * before the interceptor sets the connectionInfo.
         *
         * @see JDBCDriverInterceptor#afterMethod(EnhancedInstance, Method, Object[], Class[], Object)
         */
        if (connectInfo != null) {

            AbstractSpan span = ContextManager.createExitSpan(buildOperationName(connectInfo, method.getName(), cacheObject.getStatementName()), connectInfo.getDatabasePeer());
            Tags.DB_TYPE.set(span, "sql");
            Tags.DB_INSTANCE.set(span, connectInfo.getDatabaseName());
            Tags.DB_STATEMENT.set(span, cacheObject.getSql());
            span.setComponent(connectInfo.getComponent());

            if (Config.Plugin.MySQL.TRACE_SQL_PARAMETERS) {
                final Object[] parameters = cacheObject.getParameters();
                if (parameters != null && parameters.length > 0) {
                    int maxIndex = cacheObject.getMaxIndex();
                    String parameterString = buildParameterString(parameters, maxIndex);
                    int sqlParametersMaxLength = Config.Plugin.MySQL.SQL_PARAMETERS_MAX_LENGTH;
                    if (sqlParametersMaxLength > 0 && parameterString.length() > sqlParametersMaxLength) {
                        parameterString = parameterString.substring(0, sqlParametersMaxLength) + "...";
                    }
                    SQL_PARAMETERS.set(span, parameterString);
                }
            }

            SpanLayer.asDB(span);
        }
    }

    @Override
    public final Object afterMethod(EnhancedInstance objInst, Method method, Object[] allArguments,
        Class<?>[] argumentsTypes,
        Object ret) throws Throwable {
        StatementEnhanceInfos cacheObject = (StatementEnhanceInfos)objInst.getSkyWalkingDynamicField();
        if (cacheObject.getConnectionInfo() != null) {
            ContextManager.stopSpan();
        }
        return ret;
    }

    @Override public final void handleMethodException(EnhancedInstance objInst, Method method, Object[] allArguments,
        Class<?>[] argumentsTypes, Throwable t) {
        StatementEnhanceInfos cacheObject = (StatementEnhanceInfos)objInst.getSkyWalkingDynamicField();
        if (cacheObject.getConnectionInfo() != null) {
            ContextManager.activeSpan().errorOccurred().log(t);
        }
    }

    private String buildOperationName(ConnectionInfo connectionInfo, String methodName, String statementName) {
        return connectionInfo.getDBType() + "/JDBI/" + statementName + "/" + methodName;
    }

    private String buildParameterString(Object[] parameters, int maxIndex) {
        String parameterString = "[";
        boolean first = true;
        for (int i = 0; i < maxIndex; i++) {
            Object parameter = parameters[i];
            if (!first) {
                parameterString += ",";
            }
            parameterString += parameter;
            first = false;
        }
        parameterString += "]";
        return parameterString;
    }
}

• PreparedStatementExecuteMethodsInterceptor实现了InstanceMethodsAroundInterceptor接口，其beforeMethod方法设置DB_TYPE、DB_INSTANCE、DB_STATEMENT、SQL_PARAMETERS( Config.Plugin.MySQL.TRACE_SQL_PARAMETERS为true的话 )；其afterMethod方法在cacheObject.getConnectionInfo()不为null时执行ContextManager.stopSpan()；其handleMethodException方法在cacheObject.getConnectionInfo()不为null时执行ContextManager.activeSpan().errorOccurred().log(t)

PreparedStatementInstrumentation

skywalking-6.6.0/apm-sniffer/apm-sdk-plugin/mysql-8.x-plugin/src/main/java/org/apache/skywalking/apm/plugin/jdbc/mysql/v8/define/PreparedStatementInstrumentation.java

public class PreparedStatementInstrumentation extends AbstractMysqlInstrumentation {

    private static final String PREPARED_STATEMENT_CLASS_NAME = "com.mysql.cj.jdbc.ClientPreparedStatement";
    private static final String PREPARED_STATEMENT_SERVER_SIDE_CLASS_NAME = "com.mysql.cj.jdbc.ServerPreparedStatement";

    private static final String SERVICE_METHOD_INTERCEPTOR =  Constants.PREPARED_STATEMENT_EXECUTE_METHODS_INTERCEPTOR;

    @Override public final ConstructorInterceptPoint[] getConstructorsInterceptPoints() {
        return new ConstructorInterceptPoint[0];
    }

    @Override public InstanceMethodsInterceptPoint[] getInstanceMethodsInterceptPoints() {
        return new InstanceMethodsInterceptPoint[] {
            new InstanceMethodsInterceptPoint() {
                @Override public ElementMatcher<MethodDescription> getMethodsMatcher() {
                    return named("execute")
                        .or(named("executeQuery"))
                        .or(named("executeUpdate"))
                        .or(named("executeLargeUpdate"));
                }

                @Override public String getMethodsInterceptor() {
                    return SERVICE_METHOD_INTERCEPTOR;
                }

                @Override public boolean isOverrideArgs() {
                    return false;
                }
            }
        };
    }

    @Override protected ClassMatch enhanceClass() {
        return byMultiClassMatch(PREPARED_STATEMENT_CLASS_NAME, PREPARED_STATEMENT_SERVER_SIDE_CLASS_NAME);
    }
}

• PreparedStatementInstrumentation继承了AbstractMysqlInstrumentation，它使用org.apache.skywalking.apm.plugin.jdbc.mysql.PreparedStatementExecuteMethodsInterceptor增强了com.mysql.cj.jdbc.ClientPreparedStatement的execute、executeQuery、executeUpdate、executeLargeUpdate方法

StatementInstrumentation

skywalking-6.6.0/apm-sniffer/apm-sdk-plugin/mysql-8.x-plugin/src/main/java/org/apache/skywalking/apm/plugin/jdbc/mysql/v8/define/StatementInstrumentation.java

public class StatementInstrumentation extends AbstractMysqlInstrumentation {
    private static final String SERVICE_METHOD_INTERCEPTOR =  org.apache.skywalking.apm.plugin.jdbc.mysql.Constants.STATEMENT_EXECUTE_METHODS_INTERCEPTOR;
    public static final String MYSQL8_STATEMENT_CLASS_NAME = "com.mysql.cj.jdbc.StatementImpl";

    @Override public ConstructorInterceptPoint[] getConstructorsInterceptPoints() {
        return new ConstructorInterceptPoint[0];
    }

    @Override public InstanceMethodsInterceptPoint[] getInstanceMethodsInterceptPoints() {
        return new InstanceMethodsInterceptPoint[] {
            new InstanceMethodsInterceptPoint() {
                @Override public ElementMatcher<MethodDescription> getMethodsMatcher() {
                    return named("execute")
                        .or(named("executeQuery"))
                        .or(named("executeUpdate"))
                        .or(named("executeLargeUpdate"))
                        .or(named("executeBatchInternal"))
                        .or(named("executeUpdateInternal"))
                        .or(named("executeQuery"))
                        .or(named("executeBatch"));
                }

                @Override public String getMethodsInterceptor() {
                    return SERVICE_METHOD_INTERCEPTOR;
                }

                @Override public boolean isOverrideArgs() {
                    return false;
                }
            }
        };
    }

    @Override protected ClassMatch enhanceClass() {
        return byName(MYSQL8_STATEMENT_CLASS_NAME);
    }
}

• StatementInstrumentation继承了AbstractMysqlInstrumentation，它使用org.apache.skywalking.apm.plugin.jdbc.mysql.StatementExecuteMethodsInterceptor增强了com.mysql.cj.jdbc.StatementImpl的execute、executeQuery、executeUpdate、executeLargeUpdate、executeBatchInternal、executeUpdateInternal、executeQuery、executeBatch方法

StatementExecuteMethodsInterceptor

skywalking-6.6.0/apm-sniffer/apm-sdk-plugin/mysql-common/src/main/java/org/apache/skywalking/apm/plugin/jdbc/mysql/StatementExecuteMethodsInterceptor.java

public class StatementExecuteMethodsInterceptor implements InstanceMethodsAroundInterceptor {
    @Override
    public final void beforeMethod(EnhancedInstance objInst, Method method, Object[] allArguments,
        Class<?>[] argumentsTypes,
        MethodInterceptResult result) throws Throwable {
        StatementEnhanceInfos cacheObject = (StatementEnhanceInfos)objInst.getSkyWalkingDynamicField();
        ConnectionInfo connectInfo = cacheObject.getConnectionInfo();
        /**
         * To protected the code occur NullPointException. because mysql execute system sql when constructor method in
         * {@link com.mysql.jdbc.ConnectionImpl} class executed. but the interceptor set the connection Info after
         * the constructor method executed.
         *
         * @see JDBCDriverInterceptor#afterMethod(EnhancedInstance, Method, Object[], Class[], Object)
         */
        if (connectInfo != null) {

            AbstractSpan span = ContextManager.createExitSpan(buildOperationName(connectInfo, method.getName(), cacheObject.getStatementName()), connectInfo.getDatabasePeer());
            Tags.DB_TYPE.set(span, "sql");
            Tags.DB_INSTANCE.set(span, connectInfo.getDatabaseName());

            /**
             * The first argument of all intercept method in `com.mysql.jdbc.StatementImpl` class is SQL, except the
             * `executeBatch` method that the jdbc plugin need to trace, because of this method argument size is zero.
             */
            String sql = "";
            if (allArguments.length > 0) {
                sql = (String)allArguments[0];
            }

            Tags.DB_STATEMENT.set(span, sql);
            span.setComponent(connectInfo.getComponent());

            SpanLayer.asDB(span);
        }
    }

    @Override
    public final Object afterMethod(EnhancedInstance objInst, Method method, Object[] allArguments,
        Class<?>[] argumentsTypes,
        Object ret) throws Throwable {
        StatementEnhanceInfos cacheObject = (StatementEnhanceInfos)objInst.getSkyWalkingDynamicField();
        if (cacheObject.getConnectionInfo() != null) {
            ContextManager.stopSpan();
        }
        return ret;
    }

    @Override public final void handleMethodException(EnhancedInstance objInst, Method method, Object[] allArguments,
        Class<?>[] argumentsTypes, Throwable t) {
        StatementEnhanceInfos cacheObject = (StatementEnhanceInfos)objInst.getSkyWalkingDynamicField();
        if (cacheObject.getConnectionInfo() != null) {
            ContextManager.activeSpan().errorOccurred().log(t);
        }
    }

    private String buildOperationName(ConnectionInfo connectionInfo, String methodName, String statementName) {
        return connectionInfo.getDBType() + "/JDBI/" + statementName + "/" + methodName;
    }
}

• StatementExecuteMethodsInterceptor实现了InstanceMethodsAroundInterceptor接口，其beforeMethod方法设置DB_TYPE、DB_INSTANCE、DB_STATEMENT；其afterMethod方法在cacheObject.getConnectionInfo()不为null时执行ContextManager.stopSpan()；其handleMethodException方法在cacheObject.getConnectionInfo()不为null时执行ContextManager.activeSpan().errorOccurred().log(t)

PreparedStatementSetterInstrumentation

skywalking-6.6.0/apm-sniffer/apm-sdk-plugin/mysql-8.x-plugin/src/main/java/org/apache/skywalking/apm/plugin/jdbc/mysql/v8/define/PreparedStatementSetterInstrumentation.java

public class PreparedStatementSetterInstrumentation extends PreparedStatementInstrumentation {

    @Override
    public final InstanceMethodsInterceptPoint[] getInstanceMethodsInterceptPoints() {
        return new InstanceMethodsInterceptPoint[] {
            new PSSetterDefinitionOfJDBCInstrumentation(false)
        };
    }

}

• PreparedStatementSetterInstrumentation继承了PreparedStatementInstrumentation，其getInstanceMethodsInterceptPoints方法返回的是PSSetterDefinitionOfJDBCInstrumentation(false)

PSSetterDefinitionOfJDBCInstrumentation

skywalking-6.6.0/apm-sniffer/apm-sdk-plugin/jdbc-commons/src/main/java/org/apache/skywalking/apm/plugin/jdbc/PSSetterDefinitionOfJDBCInstrumentation.java

public class PSSetterDefinitionOfJDBCInstrumentation implements InstanceMethodsInterceptPoint {
    private final boolean ignorable;

    public PSSetterDefinitionOfJDBCInstrumentation(boolean ignorable) {
        this.ignorable = ignorable;
    }

    @Override
    public ElementMatcher<MethodDescription> getMethodsMatcher() {
        ElementMatcher.Junction<MethodDescription> matcher = none();

        if (Config.Plugin.MySQL.TRACE_SQL_PARAMETERS || Config.Plugin.POSTGRESQL.TRACE_SQL_PARAMETERS) {
            final Set<String> setters = ignorable ? PS_IGNORABLE_SETTERS : PS_SETTERS;
            for (String setter : setters) {
                matcher = matcher.or(named(setter));
            }
        }

        return matcher;
    }

    @Override
    public String getMethodsInterceptor() {
        return ignorable
            ? Constants.PREPARED_STATEMENT_IGNORABLE_SETTER_METHODS_INTERCEPTOR
            : Constants.PREPARED_STATEMENT_SETTER_METHODS_INTERCEPTOR;
    }

    @Override
    public boolean isOverrideArgs() {
        return false;
    }
}

• PSSetterDefinitionOfJDBCInstrumentation实现了InstanceMethodsInterceptPoint接口，其getMethodsMatcher方法根据ignorable使用PS_IGNORABLE_SETTERS还是PS_SETTERS去构造matcher以及methodsInterceptor

PreparedStatementNullSetterInstrumentation

skywalking-6.6.0/apm-sniffer/apm-sdk-plugin/mysql-8.x-plugin/src/main/java/org/apache/skywalking/apm/plugin/jdbc/mysql/v8/define/PreparedStatementNullSetterInstrumentation.java

public class PreparedStatementNullSetterInstrumentation extends PreparedStatementInstrumentation {

    @Override
    public final InstanceMethodsInterceptPoint[] getInstanceMethodsInterceptPoints() {
        return new InstanceMethodsInterceptPoint[] {
            new JDBCPreparedStatementNullSetterInstanceMethodsInterceptPoint()
        };
    }

}

• PreparedStatementNullSetterInstrumentation继承了PreparedStatementInstrumentation，其getInstanceMethodsInterceptPoints方法返回的是JDBCPreparedStatementNullSetterInstanceMethodsInterceptPoint

JDBCPreparedStatementNullSetterInstanceMethodsInterceptPoint

skywalking-6.6.0/apm-sniffer/apm-sdk-plugin/jdbc-commons/src/main/java/org/apache/skywalking/apm/plugin/jdbc/JDBCPreparedStatementNullSetterInstanceMethodsInterceptPoint.java

public final class JDBCPreparedStatementNullSetterInstanceMethodsInterceptPoint implements InstanceMethodsInterceptPoint {
    @Override
    public ElementMatcher<MethodDescription> getMethodsMatcher() {
        return named("setNull");
    }

    @Override
    public String getMethodsInterceptor() {
        return Constants.PREPARED_STATEMENT_NULL_SETTER_METHODS_INTERCEPTOR;
    }

    @Override
    public boolean isOverrideArgs() {
        return false;
    }
}

• JDBCPreparedStatementNullSetterInstanceMethodsInterceptPoint实现了InstanceMethodsInterceptPoint接口，它使用org.apache.skywalking.apm.plugin.jdbc.JDBCPreparedStatementNullSetterInterceptor增强setNull方法

PreparedStatementIgnoredSetterInstrumentation

skywalking-6.6.0/apm-sniffer/apm-sdk-plugin/mysql-8.x-plugin/src/main/java/org/apache/skywalking/apm/plugin/jdbc/mysql/v8/define/PreparedStatementIgnoredSetterInstrumentation.java

public class PreparedStatementIgnoredSetterInstrumentation extends PreparedStatementInstrumentation {

    @Override
    public final InstanceMethodsInterceptPoint[] getInstanceMethodsInterceptPoints() {
        return new InstanceMethodsInterceptPoint[] {
            new PSSetterDefinitionOfJDBCInstrumentation(true)
        };
    }

}

• PreparedStatementIgnoredSetterInstrumentation继承了PreparedStatementInstrumentation，其getInstanceMethodsInterceptPoints方法返回的是PSSetterDefinitionOfJDBCInstrumentation(true)

小结

skywalking的mysql-plugin提供了ConnectionImplCreateInstrumentation、ConnectionInstrumentation、CallableInstrumentation、PreparedStatementInstrumentation、StatementInstrumentation、PreparedStatementSetterInstrumentation、PreparedStatementNullSetterInstrumentation、PreparedStatementIgnoredSetterInstrumentation这几个增强

doc

• ConnectionImplCreateInstrumentation
• ConnectionInstrumentation
• CallableInstrumentation
• PreparedStatementInstrumentation
• StatementInstrumentation
• PreparedStatementSetterInstrumentation
• PreparedStatementNullSetterInstrumentation
• PreparedStatementIgnoredSetterInstrumentation