解决日志系统未初始化完成时，apollo 的加载日志没法输出问题

apollo-client/src/main/java/com/ctrip/framework/apollo/internals/DefaultConfig.java

@@ -1,5 +1,6 @@
 package com.ctrip.framework.apollo.internals;
 
+import com.ctrip.framework.apollo.core.utils.DeferredLogUtil;
 import com.ctrip.framework.apollo.enums.ConfigSourceType;
 import java.io.IOException;
 import java.io.InputStream;
@@ -58,8 +59,9 @@ private void initialize() {
       updateConfig(m_configRepository.getConfig(), m_configRepository.getSourceType());
     } catch (Throwable ex) {
       Tracer.logError(ex);
-      logger.warn("Init Apollo Local Config failed - namespace: {}, reason: {}.",
-          m_namespace, ExceptionUtil.getDetailMessage(ex));
+      String logWarnMsg = "Init Apollo Local Config failed - namespace: {}, reason: {}.";
+      logger.warn(logWarnMsg, m_namespace, ExceptionUtil.getDetailMessage(ex));
+      DeferredLogUtil.warn(logger, logWarnMsg, m_namespace, ExceptionUtil.getDetailMessage(ex));
     } finally {
       //register the change listener no matter config repository is working or not
       //so that whenever config repository is recovered, config could get changed
@@ -92,7 +94,9 @@ public String getProperty(String key, String defaultValue) {
     }
 
     if (value == null && m_configProperties.get() == null && m_warnLogRateLimiter.tryAcquire()) {
-      logger.warn("Could not load config for namespace {} from Apollo, please check whether the configs are released in Apollo! Return default value now!", m_namespace);
+      String logWarnMsg = "Could not load config for namespace {} from Apollo, please check whether the configs are released in Apollo! Return default value now!";
+      logger.warn(logWarnMsg, m_namespace);
+      DeferredLogUtil.warn(logger, logWarnMsg);
     }
 
     return value == null ? defaultValue : value;
@@ -219,7 +223,9 @@ private Properties loadFromResource(String namespace) {
         properties.load(in);
       } catch (IOException ex) {
         Tracer.logError(ex);
-        logger.error("Load resource config for namespace {} failed", namespace, ex);
+        String errMsg = "Load resource config for namespace {} failed";
+        logger.error(errMsg, namespace, ex);
+        DeferredLogUtil.error(logger, errMsg, ex);
       } finally {
         try {
           in.close();

apollo-client/src/main/java/com/ctrip/framework/apollo/internals/DefaultMetaServerProvider.java

@@ -3,6 +3,7 @@
 import com.ctrip.framework.apollo.core.ConfigConsts;
 import com.ctrip.framework.apollo.core.enums.Env;
 import com.ctrip.framework.apollo.core.spi.MetaServerProvider;
+import com.ctrip.framework.apollo.core.utils.DeferredLogUtil;
 import com.ctrip.framework.foundation.Foundation;
 import com.google.common.base.Strings;
 import org.slf4j.Logger;
@@ -36,10 +37,14 @@ private String initMetaServerAddress() {
     }
 
     if (Strings.isNullOrEmpty(metaAddress)) {
-      logger.warn("Could not find meta server address, because it is not available in neither (1) JVM system property 'apollo.meta', (2) OS env variable 'APOLLO_META' (3) property 'apollo.meta' from server.properties nor (4) property 'apollo.meta' from app.properties");
+      String logWarnMsg = "Could not find meta server address, because it is not available in neither (1) JVM system property 'apollo.meta', (2) OS env variable 'APOLLO_META' (3) property 'apollo.meta' from server.properties nor (4) property 'apollo.meta' from app.properties";
+      logger.warn(logWarnMsg);
+      DeferredLogUtil.warn(logger, logWarnMsg);
     } else {
       metaAddress = metaAddress.trim();
-      logger.info("Located meta services from apollo.meta configuration: {}!", metaAddress);
+      String logMsg = "Located meta services from apollo.meta configuration: {}!";
+      logger.info(logMsg, metaAddress);
+      DeferredLogUtil.info(logger, logMsg, metaAddress);
     }
 
     return metaAddress;

apollo-client/src/main/java/com/ctrip/framework/apollo/spring/boot/ApolloApplicationContextInitializer.java

@@ -3,6 +3,7 @@
 import com.ctrip.framework.apollo.Config;
 import com.ctrip.framework.apollo.ConfigService;
 import com.ctrip.framework.apollo.core.ConfigConsts;
+import com.ctrip.framework.apollo.core.utils.DeferredLogUtil;
 import com.ctrip.framework.apollo.spring.config.ConfigPropertySourceFactory;
 import com.ctrip.framework.apollo.spring.config.PropertySourcesConstants;
 import com.ctrip.framework.apollo.spring.util.SpringInjector;
@@ -91,7 +92,8 @@ public void initialize(ConfigurableApplicationContext context) {
   protected void initialize(ConfigurableEnvironment environment) {
 
     if (environment.getPropertySources().contains(PropertySourcesConstants.APOLLO_BOOTSTRAP_PROPERTY_SOURCE_NAME)) {
-      //already initialized
+      //already initialized ,  replay the logs that were printed before the logging system was initialized
+      DeferredLogUtil.replayTo();
       return;
     }
 

apollo-core/src/main/java/com/ctrip/framework/apollo/core/MetaDomainConsts.java

@@ -11,6 +11,7 @@
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicBoolean;
 
+import com.ctrip.framework.apollo.core.utils.DeferredLogUtil;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -90,18 +91,19 @@ private static void initMetaServerAddress(Env env) {
     for (MetaServerProvider provider : metaServerProviders) {
       metaAddress = provider.getMetaServerAddress(env);
       if (!Strings.isNullOrEmpty(metaAddress)) {
-        logger.info("Located meta server address {} for env {} from {}", metaAddress, env,
-            provider.getClass().getName());
+        String logMsg = "Located meta server address {} for env {} from {}";
+        logger.info(logMsg, metaAddress, env, provider.getClass().getName());
+        DeferredLogUtil.info(logger, logMsg, metaAddress, env, provider.getClass().getName());
         break;
       }
     }
 
     if (Strings.isNullOrEmpty(metaAddress)) {
       // Fallback to default meta address
       metaAddress = DEFAULT_META_URL;
-      logger.warn(
-          "Meta server address fallback to {} for env {}, because it is not available in all MetaServerProviders",
-          metaAddress, env);
+      String logWarnMsg = "Meta server address fallback to {} for env {}, because it is not available in all MetaServerProviders";
+      logger.warn(logWarnMsg, metaAddress, env);
+      DeferredLogUtil.warn(logger, logWarnMsg, metaAddress, env);
     }
 
     metaServerAddressCache.put(env, metaAddress.trim());

apollo-core/src/main/java/com/ctrip/framework/apollo/core/utils/DeferredLogUtil.java

@@ -0,0 +1,131 @@
+package com.ctrip.framework.apollo.core.utils;
+
+import com.google.common.cache.Cache;
+import com.google.common.cache.CacheBuilder;
+import org.slf4j.Logger;
+import org.slf4j.event.Level;
+
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicInteger;
+
+/**
+ * Delayed log printing utility class, used only for logging when Apollo is initialized
+ * @author kl (http://kailing.pub)
+ * @since 2021/5/11
+ */
+public final class DeferredLogUtil {
+
+    public static final int MAX_LOG_SIZE = 1000;
+    private static final AtomicInteger LOG_INDEX = new AtomicInteger(0);
+    private static final Cache<Integer, Line> LOG_CACHE = CacheBuilder.newBuilder()
+            .maximumSize(MAX_LOG_SIZE)
+            .expireAfterWrite(1, TimeUnit.MINUTES)
+            .build();
+
+    private DeferredLogUtil(){}
+
+    public static void debug(Logger logger, String message, Object... objects) {
+        add(logger, Level.DEBUG, message, objects, null);
+    }
+
+    public static void info(Logger logger, String message, Object... objects) {
+        add(logger, Level.INFO, message, objects, null);
+    }
+
+    public static void warn(Logger logger, String message, Object... objects) {
+        add(logger, Level.WARN, message, objects, null);
+    }
+
+    public static void error(Logger logger, String message, Throwable throwable) {
+        add(logger, Level.WARN, message, null, throwable);
+    }
+
+    private static void add(Logger logger, Level level, String message, Object[] objects, Throwable throwable) {
+        Line logLine = new Line(level, message, objects, throwable, logger);
+        LOG_CACHE.put(LOG_INDEX.incrementAndGet(), logLine);
+    }
+
+    public static void replayTo() {
+        for (int i = 1; i <= LOG_INDEX.get(); i++) {
+            Line logLine = LOG_CACHE.getIfPresent(i);
+            assert logLine != null;
+            Logger logger = logLine.getLogger();
+            Level level = logLine.getLevel();
+            String message = logLine.getMessage();
+            Object[] objects = logLine.getObjects();
+            Throwable throwable = logLine.getThrowable();
+            logTo(logger, level, message, objects, throwable);
+        }
+        clear();
+    }
+
+    private static void clear(){
+        LOG_CACHE.invalidateAll();
+        LOG_INDEX.set(0);
+    }
+
+    public static long logSize(){
+        return LOG_CACHE.size();
+    }
+
+    static void logTo(Logger logger, Level level, String message, Object[] objects, Throwable throwable) {
+        switch (level) {
+            case DEBUG:
+                logger.debug(message, objects);
+                return;
+            case INFO:
+                logger.info(message, objects);
+                return;
+            case WARN:
+                logger.warn(message, objects);
+                return;
+            case ERROR:
+                logger.error(message, throwable);
+                break;
+            default:
+                throw new IllegalStateException("Unexpected value: " + level);
+        }
+    }
+
+    static class Line {
+
+        private final Level level;
+
+        private final String message;
+
+        private final Object[] objects;
+
+        private final Throwable throwable;
+
+        private final Logger logger;
+
+        Line(Level level, String message, Object[] objects, Throwable throwable, Logger logger) {
+            this.level = level;
+            this.message = message;
+            this.objects = objects;
+            this.throwable = throwable;
+            this.logger = logger;
+        }
+
+        public Object[] getObjects() {
+            return objects;
+        }
+
+        public Logger getLogger() {
+            return logger;
+        }
+
+        Level getLevel() {
+            return this.level;
+        }
+
+        String getMessage() {
+            return this.message;
+        }
+
+        Throwable getThrowable() {
+            return this.throwable;
+        }
+
+    }
+}

apollo-core/src/main/java/com/ctrip/framework/foundation/internals/provider/DefaultApplicationProvider.java

@@ -5,6 +5,7 @@
 import java.nio.charset.StandardCharsets;
 import java.util.Properties;
 
+import com.ctrip.framework.apollo.core.utils.DeferredLogUtil;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -33,7 +34,9 @@ public void initialize() {
 
       initialize(in);
     } catch (Throwable ex) {
-      logger.error("Initialize DefaultApplicationProvider failed.", ex);
+        String errMsg = "Initialize DefaultApplicationProvider failed.";
+        logger.error(errMsg, ex);
+        DeferredLogUtil.error(logger, errMsg, ex);
     }
   }
 
@@ -52,7 +55,9 @@ public void initialize(InputStream in) {
       initAppId();
       initAccessKey();
     } catch (Throwable ex) {
-      logger.error("Initialize DefaultApplicationProvider failed.", ex);
+        String errMsg = "Initialize DefaultApplicationProvider failed.";
+        logger.error(errMsg, ex);
+        DeferredLogUtil.error(logger, errMsg, ex);
     }
   }
 
@@ -97,57 +102,66 @@ private void initAppId() {
     m_appId = System.getProperty("app.id");
     if (!Utils.isBlank(m_appId)) {
       m_appId = m_appId.trim();
-      logger.info("App ID is set to {} by app.id property from System Property", m_appId);
+      String logMsg = "App ID is set to {} by app.id property from System Property";
+      logger.info(logMsg, m_appId);
+      DeferredLogUtil.info(logger, logMsg, m_appId);
       return;
     }
 
     //2. Try to get app id from OS environment variable
     m_appId = System.getenv("APP_ID");
     if (!Utils.isBlank(m_appId)) {
       m_appId = m_appId.trim();
-      logger.info("App ID is set to {} by APP_ID property from OS environment variable", m_appId);
+      String logMsg = "App ID is set to {} by APP_ID property from OS environment variable";
+      logger.info(logMsg, m_appId);
+      DeferredLogUtil.info(logger, logMsg, m_appId);
       return;
     }
 
     // 3. Try to get app id from app.properties.
     m_appId = m_appProperties.getProperty("app.id");
     if (!Utils.isBlank(m_appId)) {
       m_appId = m_appId.trim();
-      logger.info("App ID is set to {} by app.id property from {}", m_appId,
-          APP_PROPERTIES_CLASSPATH);
+      String logMsg = "App ID is set to {} by app.id property from {}";
+      logger.info(logMsg, m_appId, APP_PROPERTIES_CLASSPATH);
+      DeferredLogUtil.info(logger, logMsg, m_appId, APP_PROPERTIES_CLASSPATH);
       return;
     }
 
     m_appId = null;
-    logger.warn("app.id is not available from System Property and {}. It is set to null",
-        APP_PROPERTIES_CLASSPATH);
+    String logWarnMsg = "app.id is not available from System Property and {}. It is set to null";
+    logger.warn(logWarnMsg, APP_PROPERTIES_CLASSPATH);
+    DeferredLogUtil.warn(logger, logWarnMsg, APP_PROPERTIES_CLASSPATH);
   }
 
   private void initAccessKey() {
     // 1. Get accesskey secret from System Property
     accessKeySecret = System.getProperty("apollo.accesskey.secret");
     if (!Utils.isBlank(accessKeySecret)) {
       accessKeySecret = accessKeySecret.trim();
-      logger
-          .info("ACCESSKEY SECRET is set by apollo.accesskey.secret property from System Property");
+      String logMsg = "ACCESSKEY SECRET is set by apollo.accesskey.secret property from System Property";
+      logger.info(logMsg);
+      DeferredLogUtil.info(logger, logMsg);
       return;
     }
 
     //2. Try to get accesskey secret from OS environment variable
     accessKeySecret = System.getenv("APOLLO_ACCESSKEY_SECRET");
     if (!Utils.isBlank(accessKeySecret)) {
       accessKeySecret = accessKeySecret.trim();
-      logger.info(
-          "ACCESSKEY SECRET is set by APOLLO_ACCESSKEY_SECRET property from OS environment variable");
+      String logMsg = "ACCESSKEY SECRET is set by APOLLO_ACCESSKEY_SECRET property from OS environment variable";
+      logger.info(logMsg);
+      DeferredLogUtil.info(logger, logMsg);
       return;
     }
 
     // 3. Try to get accesskey secret from app.properties.
     accessKeySecret = m_appProperties.getProperty("apollo.accesskey.secret");
     if (!Utils.isBlank(accessKeySecret)) {
       accessKeySecret = accessKeySecret.trim();
-      logger.info("ACCESSKEY SECRET is set by apollo.accesskey.secret property from {}",
-          APP_PROPERTIES_CLASSPATH);
+      String logMsg = "ACCESSKEY SECRET is set by apollo.accesskey.secret property from {}";
+      logger.info(logMsg, APP_PROPERTIES_CLASSPATH);
+      DeferredLogUtil.info(logger, logMsg, APP_PROPERTIES_CLASSPATH);
       return;
     }