當前系統中的日誌由各個獨立的Tomcat產生，日誌存儲的比較分散，不便於管理，而且由於採用將文件寫入NAS的方式記錄日誌，當磁盤出現故障的情況下會導致Tomcat異常。爲消除日誌實體和Tomcat程序的依賴以及解決日誌的管理問題，決定採用基於Socket的遠程日誌收集方案。
本方案需要對Tomcat的日誌系統做一些改動，具體方案如下：
一、Tomcat的改造：
Tomcat原生的日誌模塊是基於java.util.Logging改造的日誌收集器，使用和配置均比較簡單，但是不適用於一些複雜的日誌記錄需求，比如此次的遠程日誌收集方案。爲適應當前的需求，採用Log4j作爲日誌記錄器。
首先從Tomcat網站找到JULI log4j jar和JULI adapters jar兩個鏈接（http://tomcat.apache.org/download-70.cgi，在extra分類下），下載後得到tomcat-juli.jar和tomcat-juli-adapters.jar兩個jar文件，將tomcat-juli.jar拷貝至tomcat安裝目錄的bin文件夾下覆蓋原來的文件，將tomcat-juli-adapters.jar和log4j.jar拷貝至tomcat安裝目錄的lib文件夾下，同時刪除conf文件夾下的logging.properties文件。在lib目錄下建立log4j.properties文件，內容如下：
log4j.rootLogger=INFO,Console,Server
#Console Appender
log4j.appender.Console=org.apache.log4j.ConsoleAppender
log4j.appender.Console.layout=org.apache.log4j.PatternLayout
log4j.appender.Console.layout.ConversionPattern=%d{yy-MM-dd HH:mm:ss} %5p %c{1}:%L - %m%n
#Socket Appender
log4j.appender.Server=org.apache.log4j.net.SocketAppender
log4j.appender.Server.Port=4712
log4j.appender.Server.RemoteHost=192.168.1.200
log4j.appender.Server.layout.ReconnectionDelay=10000
log4j.appender.Server.application=test #這條的含義下面會說
log4j.logger.org.apache=INFO, Server
log4j.logger.org.apache.catalina.core=INFO, Server
log4j.logger.org.apache.catalina.core.ContainerBase.[Catalina].[localhost]=INFO, Server
log4j.logger.org.apache.catalina.core.ContainerBase.[Catalina].[localhost].[/manager]=INFO, Server
log4j.logger.org.apache.catalina.core.ContainerBase.[Catalina].[localhost].[/host-manager]=INFO, Server
log4j.logger.org.apache.catalina.session=INFO, Server
log4j.logger.accessLog=Server
log4j.additivity. accessLog =false
其中org.apache.log4j.net.SocketAppender就是log4j提供的基於Socket的日誌收集器，下邊三條分別指定了遠程日誌採集服務器的端口、IP和重連時間。
還有一部分是Tomcat的訪問日誌，由於訪問日誌是獨立配置在server.xml的Valve配置節中，默認如下
<Valve className="org.apache.catalina.valves.AccessLogValve" directory="logs"
prefix="localhost_access_log." suffix=".txt"
pattern="%h %l %u %t "%r" %s %b" />
我們需要提供自定義的實現用以將訪問日誌也通過Log4j輸出，代碼如下：
package com.surdoc.tomcat.extend.log;
import java.text.DateFormat;
import java.text.MessageFormat;
import java.text.SimpleDateFormat;
import java.util.Date;
import org.apache.catalina.valves.AccessLogValve;
import org.apache.log4j.Logger;
public class Log4jAccessLogValve extends AccessLogValve {
private final Logger logger = Logger.getLogger("accessLog");
protected static final String valveinfo ="com.surdoc.tomcat.extend.log.Log4JAccessLogValve";
@Override
public void log(String message) {
logger.info(message+"\n");
}
@Override
public String getInfo() {
return valveinfo;
}
@Override
protected void open() {
}
}
將這個類編譯後打成名爲log4jaccesslogvalve.jar的jar包，放到tomcat安裝目錄的lib文件夾下，注意在這裏將Logger命名爲accessLog，與log4j.properties中的log4j.logger.accessLog這個Logger對應，然後將上面提到的server.xml中的訪問日誌配置改爲此類：
<Valve className="com.surdoc.tomcat.extend.log.Log4jAccessLogValve" directory="logs"
prefix="localhost_access_log." suffix=".txt"
pattern="%h %l %u %t "%r" %s %b" />
至此Tomcat改造完畢。
二、應用中的日誌設置
我們當前的應用也採用了Log4j作爲日誌記錄器，所以只需要將log4j配置文件中的logger都指向SocketAppender就行，如下：
log4j.rootLogger=WARN, A1
#Console Appender
log4j.appender.A1=org.apache.log4j.ConsoleAppender
log4j.appender.A1.layout=org.apache.log4j.PatternLayout
log4j.appender.A1.layout.ConversionPattern=%-d{yy-MM-dd HH\:mm\:ss} [%c\:%L]-[%p] %m%n
#Socket Appender
log4j.appender.Server=org.apache.log4j.net.SocketAppender
log4j.appender.Server.Port=4712
log4j.appender.Server.RemoteHost=192.168.1.200
log4j.appender.Server.layout.ReconnectionDelay=10000
log4j.appender.Server.application=test
log4j.logger.org.apache=INFO,Server
log4j.logger.org.hibernate=INFO,Server
log4j.logger.org.springframework=INFO,Server
log4j.logger.com.sursen.webdocbase=INFO,Server
三、日誌採集服務器
Log4j中提供了一個簡單的日誌採集器org.apache.log4j.net.SimpleSocketServer，只需要將監聽端口號和server端的配置在啓動時傳入：
java -classpath log4j-1.2.17.jar org.apache.log4j.net.SimpleSocketServer 4712 log4j-server.properties
這裏我們監聽4712端口，和tomcat的SocketAppender配置一致。
至於log4j-server.properties這個文件，先看一下內容：
log4j.rootLogger=WARN,Console
log4j.appender.Console=org.apache.log4j.ConsoleAppender
log4j.appender.Console.layout=org.apache.log4j.PatternLayout
log4j.appender.Console.layout.ConversionPattern=%d{yy-MM-dd HH:mm:ss} %5p %c{1}:%L - %m%n
log4j.appender.Catalina=org.apache.log4j.DailyRollingFileAppender
log4j.appender.Catalina.File=logs/catalina.log
log4j.appender.Catalina.layout=org.apache.log4j.PatternLayout
log4j.appender.Catalina.layout.ConversionPattern=%d{yyyy.MM.dd HH:mm:ss} %5p %c{1}(%L):? %m%n
log4j.appender.Manager=org.apache.log4j.DailyRollingFileAppender
log4j.appender.Manager.File=logs/manager.log
log4j.appender.Manager.layout=org.apache.log4j.PatternLayout
log4j.appender.Manager.layout.ConversionPattern=%d{yyyy.MM.dd HH:mm:ss} %5p %c{1}(%L):? %m%n
log4j.appender.HostManager=org.apache.log4j.DailyRollingFileAppender
log4j.appender.HostManager.File=logs/host-manager.log
log4j.appender.HostManager.layout=org.apache.log4j.PatternLayout
log4j.appender.HostManager.layout.ConversionPattern=%d{yyyy.MM.dd HH:mm:ss} %5p %c{1}(%L):? %m%n
log4j.appender.AccessLog=org.apache.log4j.DailyRollingFileAppender
log4j.appender.AccessLog.File=logs/accesslog.log
log4j.appender.AccessLog.layout=org.apache.log4j.PatternLayout
log4j.appender.AccessLog.layout.ConversionPattern=%m%n
log4j.appender.R=org.apache.log4j.DailyRollingFileAppender
log4j.appender.R.File=logs/webdocbaseLog.log
log4j.appender.R.DatePattern = '.'yyyy-MM-dd
log4j.appender.R.layout=org.apache.log4j.PatternLayout
log4j.appender.R.layout.ConversionPattern=%-d{yy/MM/dd HH:mm} [%c:%L]-[%p] %m%nlog4j.appender.file.layout.ConversionPattern=%m
#Logger
log4j.logger.org.apache=INFO, Catalina
log4j.logger.org.apache.catalina.core=INFO, Catalina
log4j.logger.org.apache.catalina.core.ContainerBase.[Catalina].[localhost]=INFO, Catalina
log4j.logger.org.apache.catalina.core.ContainerBase.[Catalina].[localhost].[/manager]=INFO, Manager
log4j.logger.org.apache.catalina.core.ContainerBase.[Catalina].[localhost].[/host-manager]=INFO, HostManager
log4j.logger.accessLog=INFO, AccessLog
log4j.logger.com.sursen.webdocbase=INFO,R
和改造之前的log4j配置文件沒什麼區別，Tomcat和服務器端是通過logger名進行對應的，舉個例子：accessLog這個logger會將日誌記錄到服務器啓動目錄下的logs文件夾下的accesslog.log文件中，如果現在有兩個tomcat：tomcat1和tomcat2，他們都有名爲accessLog的logger，服務器端則會將由這兩個logger發出的日誌都寫到logs/accesslog.log這個文件中，這樣不便於區分不同tomcat的日誌，接下來我們要實現自定義的日誌收集器，我們可以通過log4j.appender.Server.application這個參數來標識一個特定的tomcat（甚至只表示一個appender），而這個值用來與服務器端conf目錄下的logroot.properties進行對應以確定其日誌存儲的路徑，logroot.properties內容像這樣：
test=logs/test
test就是log4j.appender.Server.application對應的值，這樣凡是標識了test的日誌都會記錄到logs/test這個文件夾下，對於不同的log4j.appender.Server.application需要有不同的服務器端配置，這些配置均放在服務器啓動路徑下的config/client文件夾下，其名稱與log4j.appender.Server.application這個值也是對應的，比如對於test這個配置名就是test.properties。
接下來看一下服務器端代碼，我們在Log4j提供的SimpleSocketServer基礎上進行修改，在Eclipse裏新建Java項目，先在項目中加入log4j的源碼，因爲源碼也要做一些修改：
package com.surdoc.log4j.extend.server;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.InetAddress;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.Hashtable;
import java.util.Properties;
import java.util.Set;
import org.apache.log4j.Hierarchy;
import org.apache.log4j.Level;
import org.apache.log4j.Logger;
import org.apache.log4j.PropertyConfigurator;
import org.apache.log4j.spi.RootLogger;
public class DispatchSocketServer {
static String CLIENT_DIR = "client"; //必須是client文件夾
static String CONFIG_FILE_EXT = ".properties";//配置文件後綴
static Logger cat = Logger.getLogger(DispatchSocketServer.class);
static DispatchSocketServer server;
static int port;
// key=application, value=hierarchy
Hashtable<String, Hierarchy> hierarchyMap;
String dir;
public static void main(String argv[]) {
if (argv.length == 2)
init(argv[0], argv[1]);
else
usage("Wrong number of arguments.");
try {
cat.info("Listening on port " + port);
ServerSocket serverSocket = new ServerSocket(port);
while (true) {
cat.info("Waiting to accept a new client.");
Socket socket = serverSocket.accept();
InetAddress inetAddress = socket.getInetAddress();
cat.info("Connected to client at " + inetAddress);
cat.info("Starting new socket node.");
new Thread(new SocketNode(socket, server.hierarchyMap)).start();
}
} catch (Exception e) {
e.printStackTrace();
}
}
static void usage(String msg) {
System.err.println(msg);
System.err.println("Usage: java " + DispatchSocketServer.class.getName() + " port configFile directory");
System.exit(1);
}
static void initLogFilePath(String configDir){
String configpath = configDir + File.separator + "logroot.properties";//路徑配置文件
Properties prop = new Properties();
try {
InputStream in = new FileInputStream(configpath);
prop.load(in);
in.close();
} catch (IOException e) {
e.printStackTrace();
}
//logroot.properties中的值存入系統變量
Set keys = prop.keySet();
for(Object key:keys){
String k = (String)key;
String v = (String)prop.getProperty(k);
System.setProperty(k, v);
}
}
static void init(String srvPort, String configDir) {
initLogFilePath(configDir);
try {
port = Integer.parseInt(srvPort);
} catch (java.lang.NumberFormatException e) {
e.printStackTrace();
usage("Could not interpret port number [" + srvPort + "].");
}
PropertyConfigurator.configure(configDir + File.separator + "socketserver.properties");//
server = new DispatchSocketServer(configDir);
}
public DispatchSocketServer(String configDir) {
this.dir = configDir;
hierarchyMap = new Hashtable<String, Hierarchy>(11);
configureHierarchy();
}
// This method assumes that there is no hiearchy for inetAddress
// yet. It will configure one and return it.
void configureHierarchy() {
File configFile = new File(dir + File.separator + CLIENT_DIR);
if (configFile.exists() && configFile.isDirectory()) {
String[] clients = configFile.list();
for (int i = 0; i < clients.length; i++) {
File client = new File(dir + File.separator + CLIENT_DIR + File.separator + clients[i]);
if (client.isFile()) {
Hierarchy h = new Hierarchy(new RootLogger(Level.DEBUG));
String application = clients[i].substring(0, clients[i].indexOf("."));
cat.info("Locating configuration file for " + application);
hierarchyMap.put(application, h);
//這個方法需要修改源碼
new PropertyConfigurator().doConfigure(client.getAbsolutePath(), h, clients[i].substring(0, clients[i].lastIndexOf(".")));
}
}
}
}
}
SocketNode這個類負責處理特定終端發來的日誌
package com.surdoc.log4j.extend.server;
import java.io.BufferedInputStream;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.ObjectInputStream;
import java.net.Socket;
import java.util.Hashtable;
import java.util.Properties;
import org.apache.log4j.Hierarchy;
import org.apache.log4j.Logger;
import org.apache.log4j.spi.LoggingEvent;
public class SocketNode implements Runnable{
Socket socket;
ObjectInputStream ois;
Hashtable<String, Hierarchy> hashtable;
static Logger logger = Logger.getLogger(SocketNode.class);
public SocketNode(Socket socket, Hashtable<String, Hierarchy> hashtable) {
this.socket = socket;
this.hashtable = hashtable;
try {
ois = new ObjectInputStream(new BufferedInputStream(socket.getInputStream()));
} catch (Exception e) {
logger.error("Could not open ObjectInputStream to " + socket, e);
}
}
public void run() {
LoggingEvent event;
Logger remoteLogger;
try {
if (ois != null) {
while (true) {
// read an event from the wire
event = (LoggingEvent) ois.readObject();
Object application = event.getMDC("application");
if (application != null) {
// get a logger from the hierarchy. The name of the
// logger
// is taken to be the name contained in the event.
remoteLogger = hashtable.get(application).getLogger(event.getLoggerName());
// logger.info(remoteLogger.getAppender(application.toString()));
// event.logger = remoteLogger;
// apply the logger-level filter
if (remoteLogger != null && event.getLevel().isGreaterOrEqual(remoteLogger.getEffectiveLevel())) {
// finally log the event as if was generated locally
remoteLogger.callAppenders(event);
}
}
}
}
} catch (java.io.EOFException e) {
logger.info("Caught java.io.EOFException closing conneciton.");
} catch (java.net.SocketException e) {
logger.info("Caught java.net.SocketException closing conneciton.");
} catch (IOException e) {
logger.info("Caught java.io.IOException: " + e);
logger.info("Closing connection.");
} catch (Exception e) {
logger.error("Unexpected exception. Closing conneciton.", e);
} finally {
if (ois != null) {
try {
ois.close();
} catch (Exception e) {
logger.info("Could not close connection.", e);
}
}
if (socket != null) {
try {
socket.close();
} catch (IOException ex) {
}
}
}
}
}
找到org.apache.log4j. PropertyConfigurator這個類，在其中找到下邊的方法：
Public void doConfigure(String configFileName, LoggerRepository hierarchy) {
Properties props = new Properties();
FileInputStream istream = null;
try {
istream = new FileInputStream(configFileName);
props.load(istream);
istream.close();
}
catch (Exception e) {
if (e instanceof InterruptedIOException || e instanceof InterruptedException) {
Thread.currentThread().interrupt();
}
LogLog.error("Could not read configuration file ["+configFileName+"].", e);
LogLog.error("Ignoring configuration file [" + configFileName+"].");
return;
} finally {
if(istream != null) {
try {
istream.close();
} catch(InterruptedIOException ignore) {
Thread.currentThread().interrupt();
} catch(Throwable ignore) {
}
}
}
// If we reach here, then the config file is alright.
doConfigure(props, hierarchy);
}
注意在DispatchSocketServer中如下的調用：
new PropertyConfigurator().doConfigure(client.getAbsolutePath(), h, clients[i].substring(0, clients[i].lastIndexOf(".")));
有三個參數，而上邊的方法只有兩個，下面我們就要添加這個方法：
Public void doConfigure(String configFileName, LoggerRepository hierarchy, String application) { //application就是log4j.appender.Server.application對應的值
Properties props = new Properties();
FileInputStream istream = null;
try {
istream = new FileInputStream(configFileName);
props.load(istream);
istream.close();
Set keys = props.keySet();
for(Object key:keys){
String k = (String)key;
String v = props.getProperty(k);
// 不同的配置文件中都可以用${LOGBASEPATH}來引用對應的日誌存放路徑
if(v.indexOf("${LOGBASEPATH}")!=-1){
String base = System.getProperty(application);
if(base==null || base.equals(""))
throw new RuntimeException("Base path for "+application+"is not exist!!!");
v = v.replaceAll("\\$\\{LOGBASEPATH\\}", base);
props.setProperty(k, v);
}
}
}
catch (Exception e) {
if (e instanceof InterruptedIOException || e instanceof InterruptedException) {
Thread.currentThread().interrupt();
}
LogLog.error("Could not read configuration file ["+configFileName+"].", e);
LogLog.error("Ignoring configuration file [" + configFileName+"].");
return;
} finally {
if(istream != null) {
try {
istream.close();
} catch(InterruptedIOException ignore) {
Thread.currentThread().interrupt();
} catch(Throwable ignore) {
}
}
}
// If we reach here, then the config file is alright.
doConfigure(props, hierarchy);
}
服務器端到這裏就寫完了，將整個程序編譯後打成jar包，名字可以是DispatchLogServer.jar，然後建立一個文件夾，比如logserver，將jar包放進去
然後建立logs/test文件夾，和config/test文件夾，把上邊說的logroot.properties放在config文件夾下，在這裏再建立一個配置文件socketserver.properties，負責日誌服務器的日誌輸出，內容如下：
log4j.rootCategory=INFO, STDOUT
log4j.appender.STDOUT=org.apache.log4j.ConsoleAppender
log4j.appender.STDOUT.layout=org.apache.log4j.PatternLayout
log4j.appender.STDOUT.layout.ConversionPattern=[%d{yyyy-MM-dd HH\:mm\:ss}][%5p][%5t][%l] %m%n
在config/test文件夾下建立test對應的log4j配置：
log4j.rootLogger=WARN,Console
log4j.appender.Console=org.apache.log4j.ConsoleAppender
log4j.appender.Console.layout=org.apache.log4j.PatternLayout
log4j.appender.Console.layout.ConversionPattern=%d{yy-MM-dd HH:mm:ss} %5p %c{1}:%L - %m%n
log4j.appender.Catalina=org.apache.log4j.DailyRollingFileAppender
log4j.appender.Catalina.File=${LOGBASEPATH}/catalina.log
log4j.appender.Catalina.layout=org.apache.log4j.PatternLayout
log4j.appender.Catalina.layout.ConversionPattern=%d{yyyy.MM.dd HH:mm:ss} %5p %c{1}(%L):? %m%n
log4j.appender.Manager=org.apache.log4j.DailyRollingFileAppender
log4j.appender.Manager.File=${LOGBASEPATH}/manager.log
log4j.appender.Manager.layout=org.apache.log4j.PatternLayout
log4j.appender.Manager.layout.ConversionPattern=%d{yyyy.MM.dd HH:mm:ss} %5p %c{1}(%L):? %m%n
log4j.appender.HostManager=org.apache.log4j.DailyRollingFileAppender
log4j.appender.HostManager.File=${LOGBASEPATH}/host-manager.log
log4j.appender.HostManager.layout=org.apache.log4j.PatternLayout
log4j.appender.HostManager.layout.ConversionPattern=%d{yyyy.MM.dd HH:mm:ss} %5p %c{1}(%L):? %m%n
log4j.appender.AccessLog=org.apache.log4j.DailyRollingFileAppender
log4j.appender.AccessLog.File=${LOGBASEPATH}/accesslog.log
log4j.appender.AccessLog.layout=org.apache.log4j.PatternLayout
log4j.appender.AccessLog.layout.ConversionPattern=%m%n
log4j.appender.R=org.apache.log4j.DailyRollingFileAppender
log4j.appender.R.File=${LOGBASEPATH}/webdocbaseLog.log
log4j.appender.R.DatePattern = '.'yyyy-MM-dd
log4j.appender.R.layout=org.apache.log4j.PatternLayout
log4j.appender.R.layout.ConversionPattern=%-d{yy/MM/dd HH:mm} [%c:%L]-[%p] %m%n
#Logger
log4j.logger.org.apache=INFO, Catalina
log4j.logger.org.apache.catalina.core=INFO, Catalina
log4j.logger.org.apache.catalina.core.ContainerBase.[Catalina].[localhost]=INFO, Catalina
log4j.logger.org.apache.catalina.core.ContainerBase.[Catalina].[localhost].[/manager]=INFO, Manager
log4j.logger.org.apache.catalina.core.ContainerBase.[Catalina].[localhost].[/host-manager]=INFO, HostManager
log4j.logger.accessLog=INFO, AccessLog
log4j.logger.com.sursen.webdocbase=INFO,R
注意和前邊的log4j-server.properties的區別，我們可以在裏邊通過${LOGBASEPATH}引用test對應的日誌存儲根路徑。
爲了方便運行我們在logserver文件夾下建立一個啓動腳本startup.bat內容：
java -classpath DispatchLogServer.jar com.surdoc.log4j.extend.server.DispatchSocketServer 4712 config
啓動tomcat，可以看到tomcat下的logs文件夾裏空空如也，而日誌全都傳輸到了服務器的logs/test文件夾下。