如何在运行时更改特定用户/线程的日志级别 [英] How to Change log level for particular users/threads at runtime
问题描述
我将slf4j与log4j 2.0或logback一起实现.例如，我的servlet有一个ERROR级别的记录器，我的服务器产生了servlet的100个线程.我将在运行时获得特殊用户的列表.当我检测到某些特殊用户连接时.我想将那些特殊用户/线程的日志级别更改为DEBUG，并保持其他线程的日志级别不受影响(仍然为ERROR).
I'm using slf4j with either log4j 2.0 or logback as the implementation. For example, my servlet has a logger with level ERROR, and my server spawns 100 threads of the servlet. I will get a list of special users at runtime. When I detect some of the special users connected in. I want to change the log level for those special users/threads to DEBUG, and leave other threads' log level unaffected (still ERROR).
我知道logback中的TurboFilter和log4j 2.0中的DynamicThresholdFilter，但是由于我将仅在运行时获得特殊用户列表，因此无法使用它们.
I know the TurboFilter in logback and DynamicThresholdFilter in log4j 2.0, but since I will only get the special users list at runtime, I cannot use them.
这是我的应用程序:
package com.example.logging;
import java.util.HashMap;
import java.util.Map;
import javax.servlet.http.HttpServlet;
import org.slf4j.*;
public class App extends HttpServlet {
private final Logger Logger = LoggerFactory.getLogger(App.class);
Map<String, String> map = new HashMap<String, String>();
public App() {
map.put("user1", "DEBUG");
map.put("user2", "DEBUG");
map.put("user3", "ERROR");
}
public void writeToLogFile(String userName) {
if (map.containsKey(userName)) {
// do something so that I can change the logger to the corresponding log level
}
Logger.error(userName + " error message");
// the logger is of level ERROR, so by default, this log event will not happen
// but I want it to happen for special users
if (Logger.isDebugEnabled()) {
Logger.debug(userName + " debug message");
}
}
}
这是我在log4j2.xml中的日志配置
Here is my log configuration in log4j2.xml
<?xml version="1.0" encoding="UTF-8"?>
<Configuration status="ERROR">
<Appenders>
<Console name="Console" target="SYSTEM_OUT">
<PatternLayout pattern="%-5level %class{36} %M %msg%xEx%n" />
</Console>
</Appenders>
<Loggers>
<Logger name="com.example.logging.App" level="ERROR" additivity="false">
<AppenderRef ref="Console" />
</Logger>
<Root level="DEBUG">
<AppenderRef ref="Console" />
</Root>
</Loggers>
</Configuration>
如果我调用以下方法:
App myApp = new App();
// assume the below 4 methods are called concurrently
myApp.writeToLogFile("user1");
myApp.writeToLogFile("user2");
myApp.writeToLogFile("user3");
myApp.writeToLogFile("user4");
预期输出应为:
ERROR com.example.logging.App writeToLogFile - user1 error message
DEBUG com.example.logging.App writeToLogFile - user1 debug message
ERROR com.example.logging.App writeToLogFile - user2 error message
DEBUG com.example.logging.App writeToLogFile - user2 debug message
ERROR com.example.logging.App writeToLogFile - user3 error message
ERROR com.example.logging.App writeToLogFile - user4 error message
推荐答案
I've met the same problem, and I end up using my own filter by making changes to DynamicThresholdFilter
更改应用程序:
package com.example.logging;
import java.util.HashMap;
import java.util.Map;
import javax.servlet.http.HttpServlet;
import org.slf4j.*;
public class App extends HttpServlet {
private final Logger Logger = LoggerFactory.getLogger(App.class);
Map<String, String> map = new HashMap<String, String>();
public App() {
map.put("user1", "Debug");
map.put("user2", "Debug");
map.put("user3", "Error");
}
public void writeToLogFile(String userName) {
// if the user is in the map, we put it into ThreadConext for filtering
if (map.containsKey(userName)) {
MDC.put("level", map.get(userName));
}
Logger.error(userName + " error message");
if (Logger.isDebugEnabled()) {
Logger.debug(userName + " debug message");
}
// remember to remove it
MDC.remove("level");
}
}
这是基于DynamicThresholdFilter的新定义的过滤器，我们将其称为DynamicThresholdUserFilter，您可以将其与
Here is the newly defined filter based on DynamicThresholdFilter, let's call it DynamicThresholdUserFilter, you can compare it to the source code of DynamicThresholdFilter
package com.example.logging.log4j2.plugin;
import org.apache.logging.log4j.Level;
import org.apache.logging.log4j.Marker;
import org.apache.logging.log4j.ThreadContext;
import org.apache.logging.log4j.core.LogEvent;
import org.apache.logging.log4j.core.Logger;
import org.apache.logging.log4j.core.config.plugins.Plugin;
import org.apache.logging.log4j.core.config.plugins.PluginAttribute;
import org.apache.logging.log4j.core.config.plugins.PluginFactory;
import org.apache.logging.log4j.core.filter.AbstractFilter;
import org.apache.logging.log4j.message.Message;
/**
* Compare against a log level that is associated with an MDC value.
*/
@Plugin(name = "DynamicThresholdUserFilter", category = "Core", elementType = "filter", printObject = true)
public final class DynamicThresholdUserFilter extends AbstractFilter {
private Level defaultThreshold = Level.ERROR;
private final String key;
private DynamicThresholdUserFilter(final String key, final Level defaultLevel,
final Result onMatch, final Result onMismatch) {
super(onMatch, onMismatch);
if (key == null) {
throw new NullPointerException("key cannot be null");
}
this.key = key;
this.defaultThreshold = defaultLevel;
}
public String getKey() {
return this.key;
}
@Override
public Result filter(final Logger logger, final Level level, final Marker marker, final String msg,
final Object... params) {
return filter(level);
}
@Override
public Result filter(final Logger logger, final Level level, final Marker marker, final Object msg,
final Throwable t) {
return filter(level);
}
@Override
public Result filter(final Logger logger, final Level level, final Marker marker, final Message msg,
final Throwable t) {
return filter(level);
}
@Override
public Result filter(final LogEvent event) {
return filter(event.getLevel());
}
/* biggest change here */
private Result filter(final Level level) {
final String value = ThreadContext.get(key);
if (value != null) {
Level ctxLevel = Level.toLevel(value);
if (ctxLevel == null) {
// in case the level is invalid
ctxLevel = defaultThreshold;
}
return level.isAtLeastAsSpecificAs(ctxLevel) ? onMatch : onMismatch;
}
return Result.NEUTRAL;
}
@Override
public String toString() {
final StringBuilder sb = new StringBuilder();
sb.append("key=").append(key);
sb.append(", default=").append(defaultThreshold);
return sb.toString();
}
/**
* Create the DynamicThresholdFilter.
* @param key The name of the key to compare.
* @param pairs An array of value and Level pairs.
* @param levelName The default Level.
* @param match The action to perform if a match occurs.
* @param mismatch The action to perform if no match occurs.
* @return The DynamicThresholdFilter.
*/
@PluginFactory
public static DynamicThresholdUserFilter createFilter(
@PluginAttribute("key") final String key,
@PluginAttribute("defaultThreshold") final String levelName,
@PluginAttribute("onMatch") final String match,
@PluginAttribute("onMismatch") final String mismatch) {
final Result onMatch = Result.toResult(match);
final Result onMismatch = Result.toResult(mismatch);
final Level level = Level.toLevel(levelName, Level.ERROR);
return new DynamicThresholdUserFilter(key, level, onMatch, onMismatch);
}
}
将DynamicThresholdUserFilter和程序包名称添加到您的配置文件中
Add the DynamicThresholdUserFilter and package name to your configuration file
<?xml version="1.0" encoding="UTF-8"?>
<!-- add the package name of the filter-->
<Configuration status="ERROR" packages="com.example.logging.plugin">
<!-- configuration of the new defined filter -->
<DynamicThresholdUserFilter key="level" defaultThreshold="ERROR" onMatch="ACCEPT" onMismatch="NEUTRAL" />
<Appenders>
<Console name="Console" target="SYSTEM_OUT">
<PatternLayout pattern="%-5level %class{36} %M %msg%xEx%n"/>
</Console>
</Appenders>
<Loggers>
<Logger name="com.example.logging.App" level="ERROR" additivity="false">
<AppenderRef ref="Console" />
</Logger>
<Root level="debug">
<AppenderRef ref="Console" />
</Root>
</Loggers>
</Configuration>
新定义的过滤器与DynamicThresholdFilter非常相似.区别在于DynamicThresholdFilter使用配置文件中的预定义级别作为动态阈值，而此过滤器使用在 map 中以编程方式定义的级别.
The newly defined filter is pretty similar to DynamicThresholdFilter. The difference is DynamicThresholdFilter uses the predefined level in configuration file as the dynamic threshold, while this filter uses the level programmatically defined in the map.
这篇关于如何在运行时更改特定用户/线程的日志级别的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
