Provide two start up modes and documents. (#2116)

apm-dist/bin/oapServiceNoInit.bat

+@REM
+@REM  Licensed to the Apache Software Foundation (ASF) under one or more
+@REM  contributor license agreements.  See the NOTICE file distributed with
+@REM  this work for additional information regarding copyright ownership.
+@REM  The ASF licenses this file to You under the Apache License, Version 2.0
+@REM  (the "License"); you may not use this file except in compliance with
+@REM  the License.  You may obtain a copy of the License at
+@REM
+@REM      http://www.apache.org/licenses/LICENSE-2.0
+@REM
+@REM  Unless required by applicable law or agreed to in writing, software
+@REM  distributed under the License is distributed on an "AS IS" BASIS,
+@REM  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+@REM  See the License for the specific language governing permissions and
+@REM  limitations under the License.
+
+@echo off
+
+setlocal
+set OAP_PROCESS_TITLE=Skywalking-Collector
+set OAP_HOME=%~dp0%..
+set OAP_OPTS="-Xms256M -Xmx512M -Doap.logDir=%OAP_HOME%\logs"
+
+set CLASSPATH=%OAP_HOME%\config;.;
+set CLASSPATH=%OAP_HOME%\oap-libs\*;%CLASSPATH%
+
+if defined JAVA_HOME (
+ set _EXECJAVA="%JAVA_HOME%\bin\java"
+)
+
+if not defined JAVA_HOME (
+ echo "JAVA_HOME not set."
+ set _EXECJAVA=java
+)
+
+start "%OAP_PROCESS_TITLE%" %_EXECJAVA% "%OAP_OPTS%" -cp "%CLASSPATH%" -Dmode=no-init org.apache.skywalking.oap.server.starter.OAPServerStartUp
+endlocal

apm-dist/bin/oapServiceNoInit.sh

+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+#!/usr/bin/env sh
+
+PRG="$0"
+PRGDIR=`dirname "$PRG"`
+[ -z "$OAP_HOME" ] && OAP_HOME=`cd "$PRGDIR/.." >/dev/null; pwd`
+
+OAP_LOG_DIR="${OAP_HOME}/logs"
+JAVA_OPTS=" -Xms256M -Xmx512M"
+
+if [ ! -d "${OAP_HOME}/logs" ]; then
+    mkdir -p "${OAP_LOG_DIR}"
+fi
+
+_RUNJAVA=${JAVA_HOME}/bin/java
+[ -z "$JAVA_HOME" ] && _RUNJAVA=java
+
+CLASSPATH="$OAP_HOME/config:$CLASSPATH"
+for i in "$OAP_HOME"/oap-libs/*.jar
+do
+    CLASSPATH="$i:$CLASSPATH"
+done
+
+OAP_OPTIONS=" -Doap.logDir=${OAP_LOG_DIR}"
+
+eval exec "\"$_RUNJAVA\" ${JAVA_OPTS} ${OAP_OPTIONS} -classpath $CLASSPATH -Dmode=no-init org.apache.skywalking.oap.server.starter.OAPServerStartUp \
+        2>${OAP_LOG_DIR}/oap.log 1> /dev/null &"
+
+if [ $? -eq 0 ]; then
+    sleep 1
+	echo "SkyWalking OAP started successfully!"
+else
+	echo "SkyWalking OAP started failure!"
+	exit 1
+fi

docs/en/setup/backend/backend-setup.md

@@ -3,7 +3,10 @@ First and most important thing is, SkyWalking backend startup behaviours are dri
 Understood the setting file will help you to read this document.
 
 ## Startup script
-Startup scripts are `/bin/oapService.sh`(.bat)
+The default startup scripts are `/bin/oapService.sh`(.bat). 
+Read [start up mode](backend-start-up-mode.md) document to know other options
+of starting backend.
+
 
 ## application.yml
 The core concept behind this setting file is, SkyWalking collector is based on pure modulization design. 
@@ -69,4 +72,4 @@ in storage based on rate.
 most of backend analysis capabilities based on the scripts. Here is the description of official scripts,
 which helps you to understand which metric data are in process, also could be used in alarm.
 1. [Alarm](backend-alarm.md). Alarm provides a time-series based check mechanism. You could set alarm 
-rules targeting the analysis oal metric objects.
+rules targeting the analysis oal metric objects.
\ No newline at end of file

docs/en/setup/backend/backend-start-up-mode.md

+# Start up mode
+In different deployment tool, such as k8s, you may need different startup mode.
+We provide another two optional startup modes.
+
+## Default mode
+Default mode. Do initialization works if necessary, start listen and provide service. 
+
+Run `/bin/oapService.sh`(.bat) to start in this mode. Also when use `startup.sh`(.bat) to start.
+
+## Init mode
+In this mode, oap server starts up to do initialization works, then exit.
+You could use this mode to init your storage, such as ElasticSearch indexes, MySQL and TiDB tables,
+and init data.
+
+Run `/bin/oapServiceInit.sh`(.bat) to start in this mode.
+
+## No-init mode
+In this mode, oap server starts up without initialization works,
+but it waits for ElasticSearch indexes, MySQL and TiDB tables existed,
+start listen and provide service. Meaning,
+this oap server expect another oap server to do the initialization.
+
+Run `/bin/oapServiceNoInit.sh`(.bat) to start in this mode.
\ No newline at end of file

oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/RunningMode.java

+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package org.apache.skywalking.oap.server.core;
+
+import com.google.common.base.Strings;
+
+/**
+ * The running mode of the OAP server.
+ *
+ * @author wusheng
+ */
+public class RunningMode {
+    private static String MODE = "";
+
+    private RunningMode() {
+    }
+
+    public static void setMode(String mode) {
+        if (Strings.isNullOrEmpty(mode)) {
+            return;
+        }
+        RunningMode.MODE = mode.toLowerCase();
+    }
+
+    /**
+     * Init mode, do all initialization things, and process should exit.
+     * @return true if in this status
+     */
+    public static boolean isInitMode() {
+        return MODE.equals("init");
+    }
+
+    /**
+     * No-init mode, the oap just starts up, but wouldn't do storage init.
+     * @return true if in this status.
+     */
+    public static boolean isNoInitMode() {
+        return MODE.equals("no-init");
+    }
+}

oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/storage/model/ModelInstaller.java

@@ -18,17 +18,13 @@
 
 package org.apache.skywalking.oap.server.core.storage.model;
 
-import java.util.ArrayList;
-import java.util.List;
-import org.apache.skywalking.oap.server.core.Const;
-import org.apache.skywalking.oap.server.core.CoreModule;
+import java.util.*;
+import org.apache.skywalking.oap.server.core.*;
 import org.apache.skywalking.oap.server.core.config.DownsamplingConfigService;
-import org.apache.skywalking.oap.server.core.storage.Downsampling;
-import org.apache.skywalking.oap.server.core.storage.StorageException;
+import org.apache.skywalking.oap.server.core.storage.*;
 import org.apache.skywalking.oap.server.library.client.Client;
 import org.apache.skywalking.oap.server.library.module.ModuleManager;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
+import org.slf4j.*;
 
 /**
  * @author peng-yongsheng
@@ -48,34 +44,46 @@ public abstract class ModelInstaller {
         DownsamplingConfigService downsamplingConfigService = moduleManager.find(CoreModule.NAME).provider().getService(DownsamplingConfigService.class);
 
         List<Model> models = modelGetter.getModels();
-        List<Model> downsamplingModels = new ArrayList<>();
+        List<Model> allModels = new ArrayList<>();
         models.forEach(model -> {
             if (model.isIndicator()) {
                 if (downsamplingConfigService.shouldToHour()) {
-                    downsamplingModels.add(model.copy(model.getName() + Const.ID_SPLIT + Downsampling.Hour.getName()));
+                    allModels.add(model.copy(model.getName() + Const.ID_SPLIT + Downsampling.Hour.getName()));
                 }
                 if (downsamplingConfigService.shouldToDay()) {
-                    downsamplingModels.add(model.copy(model.getName() + Const.ID_SPLIT + Downsampling.Day.getName()));
+                    allModels.add(model.copy(model.getName() + Const.ID_SPLIT + Downsampling.Day.getName()));
                 }
                 if (downsamplingConfigService.shouldToMonth()) {
-                    downsamplingModels.add(model.copy(model.getName() + Const.ID_SPLIT + Downsampling.Month.getName()));
+                    allModels.add(model.copy(model.getName() + Const.ID_SPLIT + Downsampling.Month.getName()));
                 }
             }
         });
-        downsamplingModels.addAll(models);
+        allModels.addAll(models);
 
         boolean debug = System.getProperty("debug") != null;
 
-        for (Model model : downsamplingModels) {
-            if (!isExists(client, model)) {
-                logger.info("table: {} does not exist", model.getName());
-                createTable(client, model);
-            } else if (debug) {
-                logger.info("table: {} exists", model.getName());
-                deleteTable(client, model);
-                createTable(client, model);
+        if (RunningMode.isNoInitMode()) {
+            for (Model model : allModels) {
+                while (!isExists(client, model)) {
+                    try {
+                        logger.info("table: {} does not exist. OAP is running in 'no-init' mode, waiting... retry 3s later.", model.getName());
+                        Thread.sleep(3000L);
+                    } catch (InterruptedException e) {
+                    }
+                }
+            }
+        } else {
+            for (Model model : allModels) {
+                if (!isExists(client, model)) {
+                    logger.info("table: {} does not exist", model.getName());
+                    createTable(client, model);
+                } else if (debug) {
+                    logger.info("table: {} exists", model.getName());
+                    deleteTable(client, model);
+                    createTable(client, model);
+                }
+                columnCheck(client, model);
             }
-            columnCheck(client, model);
         }
     }
 

oap-server/server-starter/src/main/java/org/apache/skywalking/oap/server/starter/OAPServerStartUp.java

@@ -18,6 +18,7 @@
 
 package org.apache.skywalking.oap.server.starter;
 
+import org.apache.skywalking.oap.server.core.RunningMode;
 import org.apache.skywalking.oap.server.library.module.*;
 import org.apache.skywalking.oap.server.starter.config.*;
 import org.slf4j.*;
@@ -30,14 +31,16 @@ public class OAPServerStartUp {
     private static final Logger logger = LoggerFactory.getLogger(OAPServerStartUp.class);
 
     public static void main(String[] args) {
+        String mode = System.getProperty("mode");
+        RunningMode.setMode(mode);
+
         ApplicationConfigLoader configLoader = new ApplicationConfigLoader();
         ModuleManager manager = new ModuleManager();
         try {
             ApplicationConfiguration applicationConfiguration = configLoader.load();
             manager.init(applicationConfiguration);
 
-            String mode = System.getProperty("mode");
-            if ("init".equals(mode)) {
+            if (RunningMode.isInitMode()) {
                 logger.info("OAP starts up in init mode successfully, exit now...");
                 System.exit(0);
             }