我使用tomcat7作为应用程序服务器运行我的java Web应用程序（.war），当我重新启动tomcat时需要20-25分钟来部署可能的战争文件。 我重新启动tomcat时得到这个日志：
Sep 24, 2016 9:45:29 AM org.apache.catalina.core.StandardService startInternal
INFO: Starting service Catalina
Sep 24, 2016 9:45:29 AM org.apache.catalina.core.StandardEngine startInternal
INFO: Starting Servlet Engine: Apache Tomcat/7.0.68 (Ubuntu)
Sep 24, 2016 9:45:29 AM org.apache.catalina.startup.HostConfig deployWAR
INFO: Deploying web application archive /var/lib/tomcat7/webapps/tnu.war
Sep 24, 2016 9:45:30 AM org.apache.catalina.loader.WebappClassLoaderBase validateJarFile
INFO: validateJarFile(/var/lib/tomcat7/webapps/tnu/WEB-INF/lib/javax.servlet-api-3.0.1.jar) - jar not loaded. See Servlet Spec 3.0, section 10.7.2. Offending class: javax/servlet/Servlet.class
Sep 24, 2016 9:45:33 AM org.apache.catalina.startup.TldConfig execute
INFO: At least one JAR was scanned for TLDs yet contained no TLDs. Enable debug logging for this logger for a complete list of JARs that were scanned but no TLDs were found in them. Skipping unneeded JARs during scanning can improve startup time and JSP compilation time.
Sep 24, 2016 9:46:51 AM org.apache.catalina.startup.ClassLoaderFactory validateFile
WARNING: Problem with directory [/usr/share/tomcat7/common/classes], exists: [false], isDirectory: [false], canRead: [false]
Sep 24, 2016 9:46:51 AM org.apache.catalina.startup.ClassLoaderFactory validateFile
WARNING: Problem with directory [/usr/share/tomcat7/common], exists: [false], isDirectory: [false], canRead: [false]
Sep 24, 2016 9:46:51 AM org.apache.catalina.startup.ClassLoaderFactory validateFile
WARNING: Problem with directory [/usr/share/tomcat7/server/classes], exists: [false], isDirectory: [false], canRead: [false]
Sep 24, 2016 9:46:51 AM org.apache.catalina.startup.ClassLoaderFactory validateFile
WARNING: Problem with directory [/usr/share/tomcat7/server], exists: [false], isDirectory: [false], canRead: [false]
Sep 24, 2016 9:46:51 AM org.apache.catalina.startup.ClassLoaderFactory validateFile
WARNING: Problem with directory [/usr/share/tomcat7/shared/classes], exists: [false], isDirectory: [false], canRead: [false]
Sep 24, 2016 9:46:51 AM org.apache.catalina.startup.ClassLoaderFactory validateFile
WARNING: Problem with directory [/usr/share/tomcat7/shared], exists: [false], isDirectory: [false], canRead: [false]
Sep 24, 2016 9:46:52 AM org.apache.catalina.startup.VersionLoggerListener log
INFO: Server version: Apache Tomcat/7.0.68 (Ubuntu)
Sep 24, 2016 9:46:52 AM org.apache.catalina.startup.VersionLoggerListener log
INFO: Server built: Jun 27 2016 18:13:17 UTC
Sep 24, 2016 9:46:52 AM org.apache.catalina.startup.VersionLoggerListener log
INFO: Server number: 7.0.68.0
Sep 24, 2016 9:46:52 AM org.apache.catalina.startup.VersionLoggerListener log
INFO: OS Name: Linux
Sep 24, 2016 9:46:52 AM org.apache.catalina.startup.VersionLoggerListener log
INFO: OS Version: 4.4.0-36-generic
INFO: Server version: Apache Tomcat/7.0.68 (Ubuntu)
Sep 24, 2016 9:46:52 AM org.apache.catalina.startup.VersionLoggerListener log
INFO: Server built: Jun 27 2016 18:13:17 UTC
Sep 24, 2016 9:46:52 AM org.apache.catalina.startup.VersionLoggerListener log
INFO: Server number: 7.0.68.0
Sep 24, 2016 9:46:52 AM org.apache.catalina.startup.VersionLoggerListener log
INFO: OS Name: Linux
Sep 24, 2016 9:46:52 AM org.apache.catalina.startup.VersionLoggerListener log
INFO: OS Version: 4.4.0-36-generic
Sep 24, 2016 9:46:52 AM org.apache.catalina.startup.VersionLoggerListener log
INFO: Architecture: amd64
Sep 24, 2016 9:46:52 AM org.apache.catalina.startup.VersionLoggerListener log
INFO: Java Home: /usr/lib/jvm/java-8-openjdk-amd64/jre
Sep 24, 2016 9:46:52 AM org.apache.catalina.startup.VersionLoggerListener log
INFO: JVM Version: 1.8.0_91-8u91-b14-3ubuntu1~16.04.1-b14
Sep 24, 2016 9:46:52 AM org.apache.catalina.startup.VersionLoggerListener log
INFO: JVM Vendor: Oracle Corporation
Sep 24, 2016 9:46:52 AM org.apache.catalina.startup.VersionLoggerListener log
INFO: CATALINA_BASE: /var/lib/tomcat7
Sep 24, 2016 9:46:52 AM org.apache.catalina.startup.VersionLoggerListener log
INFO: CATALINA_HOME: /usr/share/tomcat7
Sep 24, 2016 9:46:52 AM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -Djava.util.logging.config.file=/var/lib/tomcat7/conf/logging.properties
Sep 24, 2016 9:46:52 AM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -Djava.util.logging.manager=org.apache.juli.ClassLoaderLogManager
Sep 24, 2016 9:46:52 AM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -Djava.awt.headless=true
Sep 24, 2016 9:46:52 AM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -Xmx128m
Sep 24, 2016 9:46:52 AM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -XX:+UseConcMarkSweepGC
Sep 24, 2016 9:46:52 AM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -Djava.endorsed.dirs=/usr/share/tomcat7/endorsed
Sep 24, 2016 9:46:52 AM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -Dcatalina.base=/var/lib/tomcat7
Sep 24, 2016 9:46:52 AM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -Dcatalina.home=/usr/share/tomcat7
Sep 24, 2016 9:46:52 AM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -Djava.io.tmpdir=/tmp/tomcat7-tomcat7-tmp
INFO: Command line argument: -Djava.io.tmpdir=/tmp/tomcat7-tomcat7-tmp
Sep 24, 2016 9:46:52 AM org.apache.coyote.AbstractProtocol init
INFO: Initializing ProtocolHandler ["http-bio-8080"]
Sep 24, 2016 9:46:52 AM org.apache.catalina.startup.Catalina load
INFO: Initialization processed in 744 ms
Sep 24, 2016 9:46:52 AM org.apache.catalina.core.StandardService startInternal
INFO: Starting service Catalina
Sep 24, 2016 9:46:52 AM org.apache.catalina.core.StandardEngine startInternal
INFO: Starting Servlet Engine: Apache Tomcat/7.0.68 (Ubuntu)
Sep 24, 2016 9:46:52 AM org.apache.catalina.startup.HostConfig deployWAR
INFO: Deploying web application archive /var/lib/tomcat7/webapps/tnu.war
Sep 24, 2016 9:46:53 AM org.apache.catalina.loader.WebappClassLoaderBase validateJarFile
INFO: validateJarFile(/var/lib/tomcat7/webapps/tnu/WEB-INF/lib/javax.servlet-api-3.0.1.jar) - jar not loaded. See Servlet Spec 3.0, section 10.7.2. Offending class: javax/servlet/Servlet.class
Sep 24, 2016 9:46:56 AM org.apache.catalina.startup.TldConfig execute
INFO: At least one JAR was scanned for TLDs yet contained no TLDs. Enable debug logging for this logger for a complete list of JARs that were scanned but no TLDs were found in them. Skipping unneeded JARs during scanning can improve startup time and JSP compilation time.
Sep 24, 2016 10:03:01 AM org.apache.catalina.util.SessionIdGeneratorBase createSecureRandom
INFO: Creation of SecureRandom instance for session ID generation using [SHA1PRNG] took [965,010] milliseconds.
log4j:WARN No such property [maxBackupIndex] in org.apache.log4j.DailyRollingFileAppender.
log4j:WARN No such property [maxFileSize] in org.apache.log4j.DailyRollingFileAppender.
24 Sep 2016 10:03:01,669 - [localhost-startStop-1] DEBUG [org.jboss.logging] [] - Logging Provider: org.jboss.logging.Log4jLoggerProvider
24 Sep 2016 10:03:01,694 - [localhost-startStop-1] DEBUG [logging.loggers.YWLogger] [] - Sat Sep 24 10:03:01 UTC 2016 - [ ConstantReader ] File Found
File Found
24 Sep 2016 10:03:01,697 - [localhost-startStop-1] DEBUG [reqfilter.interceptor.MobReqFilter] [] - MobRequestFilter : init + webapp path : /var/lib/tomcat7/webapps/tnu/
24 Sep 2016 10:03:01,698 - [localhost-startStop-1] DEBUG [reqfilter.interceptor.MobReqFilter] [] - init params : WEB-INF/classes/log4j.properties
Sep 24, 2016 10:03:05 AM org.apache.catalina.startup.HostConfig deployWAR
INFO: Deployment of web application archive /var/lib/tomcat7/webapps/tnu.war has finished in 973,344 ms
Sep 24, 2016 10:03:05 AM org.apache.catalina.startup.HostConfig deployDirectory
INFO: Deploying web application directory /var/lib/tomcat7/webapps/ROOT
Sep 24, 2016 10:03:05 AM org.apache.catalina.core.StandardContext setPath
WARNING: A context path must either be an empty string or start with a '/' and do not end with a '/'. The path [/] does not meet these criteria and has been changed to []
Sep 24, 2016 10:03:06 AM org.apache.catalina.startup.TldConfig execute
INFO: At least one JAR was scanned for TLDs yet contained no TLDs. Enable debug logging for this logger for a complete list of JARs that were scanned but no TLDs were found in them. Skipping unneeded JARs during scanning can improve startup time and JSP compilation time.
Sep 24, 2016 10:03:06 AM org.apache.catalina.startup.HostConfig deployDirectory
INFO: Deployment of web application directory /var/lib/tomcat7/webapps/ROOT has finished in 331 ms
Sep 24, 2016 10:03:06 AM org.apache.coyote.AbstractProtocol start
INFO: Starting ProtocolHandler ["http-bio-8080"]
Sep 24, 2016 10:03:06 AM org.apache.catalina.startup.Catalina start
INFO: Server startup in 973768 ms
我重新启动tomcat7后必须等待20-25分钟。这是一个解决方案吗？
注意：OS - ubuntu 14.04 on digitalocean cloud。
答案 0 :(得分：5)
your normal html
<iframe src="page that should be reloaded.html">old browser</iframe>
<script>
function reload(){ document.getElementsByTagName("iframe")[0].reload();
}
</script>
这是需要大量服务器时间的过程。 创建SecureRandom本身需要16.0835 Minutes。
幸运的是，Apache wiki有一个解决方法：
Tomcat 7+严重依赖SecureRandom类为其会话ID和其他地方提供随机值。如果用于初始化SecureRandom的熵源缺少熵，则可能会在启动期间导致延迟，具体取决于您的JRE。发生这种情况时，您会在日志中看到警告，例如：
INFO: Creation of SecureRandom instance for session ID generation using [SHA1PRNG] took [965,010] milliseconds.有一种方法可以通过设置以下系统属性来配置JRE以使用非阻塞熵源： -
<DATE> org.apache.catalina.util.SessionIdGenerator createSecureRandom INFO: Creation of SecureRandom instance for session ID generation using [SHA1PRNG] took [5172] milliseconds.
答案 1 :(得分：1)
对于无头服务器，Haveged是一种可能的解决方案，因为tomcat由于低熵而无法启动。使用Haveged而不是urandom的一个重要优点是，您不必在安全性上妥协以加速tomcat启动。我有一个类似的帖子。 Tomcat takes too much time to start - Java SecureRandom。 阅读此Tomcat takes too long to start