ICEfaces
  1. ICEfaces
  2. ICE-1473

cpu overload from fetching CSS resources with gzip encoding

          Details

          • Type: Bug Bug
          • Status: Closed
          • Priority: Major Major
          • Resolution: Fixed
          • Affects Version/s: 1.6DR#3
          • Fix Version/s: 1.6DR#4, 1.6
          • Component/s: Framework
          • Labels:
            None
          • Environment:
            multiprocessor server, jdk 1.5
          • Workaround Exists:
            Yes
          • Workaround Description:
            turn off accept gzip in the browser; however, this is not likely an acceptable workaround for most users

            Description


            CSS resources can be served stressfully with the following script:

            while true; do for x in 1 2 3 4 5 6 7 8 9 0; do curl -H "Accept-Encoding: gzip,deflate" -O http://vorlon.ice:8080/component-showcase/xmlhttp/css/xp/css-images/over-right-mid.gif -O http://vorlon.ice:8080/component-showcase/xmlhttp/css/xp/xp.css& done; sleep 1; done

            When this is run against a multiprocessor machine (both mac and linux have been tested),
            after a short period the CPU utilization will go to 100% and will not subside until the server is killed. A typical thread in this state is the following:

              [1] java.util.zip.Deflater.deflateBytes (native method)
              [2] java.util.zip.Deflater.deflate (Deflater.java:284)
              [3] java.util.zip.DeflaterOutputStream.deflate (DeflaterOutputStream.java:154)
              [4] java.util.zip.DeflaterOutputStream.write (DeflaterOutputStream.java:114)
              [5] java.util.zip.GZIPOutputStream.write (GZIPOutputStream.java:72)
              [6] com.icesoft.faces.webapp.http.common.standard.CompressingServer.copy (CompressingServer.java:72)
              [7] com.icesoft.faces.webapp.http.common.standard.CompressingServer.access$200 (CompressingServer.java:15)
              [8] com.icesoft.faces.webapp.http.common.standard.CompressingServer$CompressingResponse.writeBodyFrom (CompressingServer.java:65)
              [9] com.icesoft.faces.webapp.http.core.ServeCSSResource$1.respond (ServeCSSResource.java:32)
              [10] com.icesoft.faces.webapp.http.common.standard.CacheControlledServer$EnhancedRequest$1.respond (CacheControlledServer.java:70)
              [11] com.icesoft.faces.webapp.http.common.standard.CompressingServer$CompressingRequest$1.respond (CompressingServer.java:44)
              [12] com.icesoft.faces.webapp.http.servlet.ServletRequestResponse.respondWith (ServletRequestResponse.java:121)
              [13] com.icesoft.faces.webapp.http.common.standard.CompressingServer$CompressingRequest.respondWith (CompressingServer.java:42)
              [14] com.icesoft.faces.webapp.http.common.standard.CacheControlledServer$EnhancedRequest.respondWith (CacheControlledServer.java:63)
              [15] com.icesoft.faces.webapp.http.core.ServeCSSResource.service (ServeCSSResource.java:29)
              [16] com.icesoft.faces.webapp.http.common.standard.CacheControlledServer.service (CacheControlledServer.java:42)
              [17] com.icesoft.faces.webapp.http.common.standard.PathDispatcherServer$Matcher.serviceOnMatch (PathDispatcherServer.java:50)
              [18] com.icesoft.faces.webapp.http.common.standard.PathDispatcherServer.service (PathDispatcherServer.java:19)
              [19] com.icesoft.faces.webapp.http.common.standard.CompressingServer.service (CompressingServer.java:26)
              [20] com.icesoft.faces.webapp.http.core.ResourceServer.service (ResourceServer.java:30)
              [21] com.icesoft.faces.webapp.http.servlet.BasicAdaptingServlet.service (BasicAdaptingServlet.java:16)
              [22] com.icesoft.faces.webapp.http.servlet.PathDispatcher$Matcher.serviceOnMatch (PathDispatcher.java:41)
              [23] com.icesoft.faces.webapp.http.servlet.PathDispatcher.service (PathDispatcher.java:18)
              [24] com.icesoft.faces.webapp.http.servlet.MainServlet.service (MainServlet.java:47)
              [25] javax.servlet.http.HttpServlet.service (HttpServlet.java:802)
              [26] org.apache.catalina.core.ApplicationFilterChain.internalDoFilter (ApplicationFilterChain.java:237)
              [27] org.apache.catalina.core.ApplicationFilterChain.doFilter (ApplicationFilterChain.java:157)
              [28] org.apache.catalina.core.StandardWrapperValve.invoke (StandardWrapperValve.java:214)
              [29] org.apache.catalina.core.StandardValveContext.invokeNext (StandardValveContext.java:104)
              [30] org.apache.catalina.core.StandardPipeline.invoke (StandardPipeline.java:520)
              [31] org.apache.catalina.core.StandardContextValve.invokeInternal (StandardContextValve.java:198)
              [32] org.apache.catalina.core.StandardContextValve.invoke (StandardContextValve.java:152)
              [33] org.apache.catalina.core.StandardValveContext.invokeNext (StandardValveContext.java:104)
              [34] org.apache.catalina.core.StandardPipeline.invoke (StandardPipeline.java:520)
              [35] org.apache.catalina.core.StandardHostValve.invoke (StandardHostValve.java:137)
              [36] org.apache.catalina.core.StandardValveContext.invokeNext (StandardValveContext.java:104)
              [37] org.apache.catalina.valves.ErrorReportValve.invoke (ErrorReportValve.java:118)
              [38] org.apache.catalina.core.StandardValveContext.invokeNext (StandardValveContext.java:102)
              [39] org.apache.catalina.core.StandardPipeline.invoke (StandardPipeline.java:520)
              [40] org.apache.catalina.core.StandardEngineValve.invoke (StandardEngineValve.java:109)
              [41] org.apache.catalina.core.StandardValveContext.invokeNext (StandardValveContext.java:104)
              [42] org.apache.catalina.core.StandardPipeline.invoke (StandardPipeline.java:520)
              [43] org.apache.catalina.core.ContainerBase.invoke (ContainerBase.java:929)
              [44] org.apache.coyote.tomcat5.CoyoteAdapter.service (CoyoteAdapter.java:160)
              [45] org.apache.coyote.http11.Http11Processor.process (Http11Processor.java:799)
              [46] org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.processConnection (Http11Protocol.java:705)
              [47] org.apache.tomcat.util.net.TcpWorkerThread.runIt (PoolTcpEndpoint.java:577)
              [48] org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run (ThreadPool.java:683)
              [49] java.lang.Thread.run (Thread.java:613)

            By instrumenting the CompressingServer, it has been verified that the CPU activity is occurring only in the java.util.zip package. This is likely a zip implementation bug (lack of thread safety, perhaps in a native library) so the fix may be either to disable gzip encoding or to apply our own locking to ensure single threaded access to the gzip library.

              Activity

              Ascending order - Click to sort in descending order
              Hide
              Permalink
              Ted Goddard added a comment -

              Rather than compress static resources each time they are served, it may be preferable to pre-compress the resources, storing the compressed versions on the filesystem, and simply serve the compressed versions.

              Show
              Ted Goddard added a comment - Rather than compress static resources each time they are served, it may be preferable to pre-compress the resources, storing the compressed versions on the filesystem, and simply serve the compressed versions.
              Hide
              Permalink
              Ted Goddard added a comment -

              This bug will spoil the JavaOne booth demos; we need to either add configuration to disable gzip or find a fix.

              Show
              Ted Goddard added a comment - This bug will spoil the JavaOne booth demos; we need to either add configuration to disable gzip or find a fix.
              Hide
              Permalink
              Mircea Toma added a comment -

              There is the configuration parameter 'com.icefaces.faces.compressResources' that can turn on/off the GZIP compression.

              I can have another look at the implementation to see how can I fix it.

              Show
              Mircea Toma added a comment - There is the configuration parameter 'com.icefaces.faces.compressResources' that can turn on/off the GZIP compression. I can have another look at the implementation to see how can I fix it.
              Hide
              Permalink
              Mircea Toma added a comment -

              Refactor so that the stream is not an instance variable (obviously that would force the code to be synchronized). Tested with the script and the process CPU usage stays below 10%.

              Show
              Mircea Toma added a comment - Refactor so that the stream is not an instance variable (obviously that would force the code to be synchronized). Tested with the script and the process CPU usage stays below 10%.
              Hide
              Permalink
              Ted Goddard added a comment -

              Tested on a four CPU machine and confirmed fixed.

              Show
              Ted Goddard added a comment - Tested on a four CPU machine and confirmed fixed.

                People

                • Assignee:
                  Unassigned
                  Reporter:
                  Ted Goddard
                • Votes:
                  0 Vote for this issue
                  Watchers:
                  0 Start watching this issue

                  Dates

                  • Created:
                    Updated:
                    Resolved: