[jira] [Updated] (OOZIE-2651) Set javax.xml.parsers.DocumentBuilderFactory sys prop to make XML handling faster
[ https://issues.apache.org/jira/browse/OOZIE-2651?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ] Robert Kanter updated OOZIE-2651: - Attachment: OOZIE-2651.005.patch The 005 patch: - Adds unit tests > Set javax.xml.parsers.DocumentBuilderFactory sys prop to make XML handling > faster > - > > Key: OOZIE-2651 > URL: https://issues.apache.org/jira/browse/OOZIE-2651 > Project: Oozie > Issue Type: Improvement > Components: core >Affects Versions: trunk >Reporter: Robert Kanter >Assignee: Robert Kanter > Attachments: OOZIE-2651.001.patch, OOZIE-2651.002.patch, > OOZIE-2651.003.patch, OOZIE-2651.004.patch, OOZIE-2651.005.patch > > > We noticed from some jstacks that Oozie was spending a lot of time looking > for XML related jars (we do a lot of XML parsing in Oozie and Hadoop code). > For instance, we'd see hundreds of threads blocked here > {noformat} > "pool-5-thread-57" prio=10 tid=0x7f9579923000 nid=0x6b7f waiting for > monitor entry [0x7f94225e3000] >java.lang.Thread.State: BLOCKED (on object monitor) > at > org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1559) > - waiting to lock <0x000500026148> (a > org.apache.catalina.loader.WebappClassLoader) > at > org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1526) > at > javax.xml.parsers.FactoryFinder.getProviderClass(FactoryFinder.java:117) > at javax.xml.parsers.FactoryFinder.newInstance(FactoryFinder.java:178) > at > javax.xml.parsers.FactoryFinder.findJarServiceProvider(FactoryFinder.java:333) > at javax.xml.parsers.FactoryFinder.find(FactoryFinder.java:255) > at > javax.xml.parsers.DocumentBuilderFactory.newInstance(DocumentBuilderFactory.java:121) > at > org.apache.hadoop.conf.Configuration.loadResource(Configuration.java:2526) > at > org.apache.hadoop.conf.Configuration.loadResources(Configuration.java:2503) > at > org.apache.hadoop.conf.Configuration.getProps(Configuration.java:2409) > - locked <0x0007eac5ea28> (a org.apache.hadoop.conf.Configuration) > at org.apache.hadoop.conf.Configuration.set(Configuration.java:1144) > at org.apache.hadoop.conf.Configuration.set(Configuration.java:1116) > at org.apache.oozie.util.XConfiguration.copy(XConfiguration.java:206) > ... > {noformat} > There's nothing we can do about the lock at the {{WebappClassLoader}}, but by > setting the {{javax.xml.parsers.DocumentBuilderFactory}} system property to > {{org.apache.xerces.jaxp.DocumentBuilderFactoryImpl}}, we can speed this up a > lot by getting rid of all of the searching that it's doing to find the > implementation. > See > https://docs.oracle.com/javase/7/docs/api/javax/xml/parsers/DocumentBuilderFactory.html#newInstance() > > and > https://www.databasesandlife.com/java-always-explicitly-specify-which-xml-parser-to-use/ > In our testing, we had a metric around creating a new {{JobClient}}, which > also calls {{DocumentBuilderFactory.newInstance}}, and it dropped from ~3min > max to ~2sec max (not an exact test of the savings here). And we also didn't > see so much blocking on this in the jstacks anymore. -- This message was sent by Atlassian JIRA (v6.4.14#64029)
[jira] [Updated] (OOZIE-2651) Set javax.xml.parsers.DocumentBuilderFactory sys prop to make XML handling faster
[ https://issues.apache.org/jira/browse/OOZIE-2651?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ] Robert Kanter updated OOZIE-2651: - Attachment: OOZIE-2651.004.patch The 004 patch removes the tab. > Set javax.xml.parsers.DocumentBuilderFactory sys prop to make XML handling > faster > - > > Key: OOZIE-2651 > URL: https://issues.apache.org/jira/browse/OOZIE-2651 > Project: Oozie > Issue Type: Improvement > Components: core >Affects Versions: trunk >Reporter: Robert Kanter >Assignee: Robert Kanter > Attachments: OOZIE-2651.001.patch, OOZIE-2651.002.patch, > OOZIE-2651.003.patch, OOZIE-2651.004.patch > > > We noticed from some jstacks that Oozie was spending a lot of time looking > for XML related jars (we do a lot of XML parsing in Oozie and Hadoop code). > For instance, we'd see hundreds of threads blocked here > {noformat} > "pool-5-thread-57" prio=10 tid=0x7f9579923000 nid=0x6b7f waiting for > monitor entry [0x7f94225e3000] >java.lang.Thread.State: BLOCKED (on object monitor) > at > org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1559) > - waiting to lock <0x000500026148> (a > org.apache.catalina.loader.WebappClassLoader) > at > org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1526) > at > javax.xml.parsers.FactoryFinder.getProviderClass(FactoryFinder.java:117) > at javax.xml.parsers.FactoryFinder.newInstance(FactoryFinder.java:178) > at > javax.xml.parsers.FactoryFinder.findJarServiceProvider(FactoryFinder.java:333) > at javax.xml.parsers.FactoryFinder.find(FactoryFinder.java:255) > at > javax.xml.parsers.DocumentBuilderFactory.newInstance(DocumentBuilderFactory.java:121) > at > org.apache.hadoop.conf.Configuration.loadResource(Configuration.java:2526) > at > org.apache.hadoop.conf.Configuration.loadResources(Configuration.java:2503) > at > org.apache.hadoop.conf.Configuration.getProps(Configuration.java:2409) > - locked <0x0007eac5ea28> (a org.apache.hadoop.conf.Configuration) > at org.apache.hadoop.conf.Configuration.set(Configuration.java:1144) > at org.apache.hadoop.conf.Configuration.set(Configuration.java:1116) > at org.apache.oozie.util.XConfiguration.copy(XConfiguration.java:206) > ... > {noformat} > There's nothing we can do about the lock at the {{WebappClassLoader}}, but by > setting the {{javax.xml.parsers.DocumentBuilderFactory}} system property to > {{org.apache.xerces.jaxp.DocumentBuilderFactoryImpl}}, we can speed this up a > lot by getting rid of all of the searching that it's doing to find the > implementation. > See > https://docs.oracle.com/javase/7/docs/api/javax/xml/parsers/DocumentBuilderFactory.html#newInstance() > > and > https://www.databasesandlife.com/java-always-explicitly-specify-which-xml-parser-to-use/ > In our testing, we had a metric around creating a new {{JobClient}}, which > also calls {{DocumentBuilderFactory.newInstance}}, and it dropped from ~3min > max to ~2sec max (not an exact test of the savings here). And we also didn't > see so much blocking on this in the jstacks anymore. -- This message was sent by Atlassian JIRA (v6.3.15#6346)
[jira] [Updated] (OOZIE-2651) Set javax.xml.parsers.DocumentBuilderFactory sys prop to make XML handling faster
[ https://issues.apache.org/jira/browse/OOZIE-2651?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ] Robert Kanter updated OOZIE-2651: - Attachment: OOZIE-2651.003.patch Rebased the patch again (003) because it didn't apply anymore due to oozie-default.xml changes. I also fixed the grammar in the config description. [~gezapeti], [~pbacsko] can one of you review? > Set javax.xml.parsers.DocumentBuilderFactory sys prop to make XML handling > faster > - > > Key: OOZIE-2651 > URL: https://issues.apache.org/jira/browse/OOZIE-2651 > Project: Oozie > Issue Type: Improvement > Components: core >Affects Versions: trunk >Reporter: Robert Kanter >Assignee: Robert Kanter > Attachments: OOZIE-2651.001.patch, OOZIE-2651.002.patch, > OOZIE-2651.003.patch > > > We noticed from some jstacks that Oozie was spending a lot of time looking > for XML related jars (we do a lot of XML parsing in Oozie and Hadoop code). > For instance, we'd see hundreds of threads blocked here > {noformat} > "pool-5-thread-57" prio=10 tid=0x7f9579923000 nid=0x6b7f waiting for > monitor entry [0x7f94225e3000] >java.lang.Thread.State: BLOCKED (on object monitor) > at > org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1559) > - waiting to lock <0x000500026148> (a > org.apache.catalina.loader.WebappClassLoader) > at > org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1526) > at > javax.xml.parsers.FactoryFinder.getProviderClass(FactoryFinder.java:117) > at javax.xml.parsers.FactoryFinder.newInstance(FactoryFinder.java:178) > at > javax.xml.parsers.FactoryFinder.findJarServiceProvider(FactoryFinder.java:333) > at javax.xml.parsers.FactoryFinder.find(FactoryFinder.java:255) > at > javax.xml.parsers.DocumentBuilderFactory.newInstance(DocumentBuilderFactory.java:121) > at > org.apache.hadoop.conf.Configuration.loadResource(Configuration.java:2526) > at > org.apache.hadoop.conf.Configuration.loadResources(Configuration.java:2503) > at > org.apache.hadoop.conf.Configuration.getProps(Configuration.java:2409) > - locked <0x0007eac5ea28> (a org.apache.hadoop.conf.Configuration) > at org.apache.hadoop.conf.Configuration.set(Configuration.java:1144) > at org.apache.hadoop.conf.Configuration.set(Configuration.java:1116) > at org.apache.oozie.util.XConfiguration.copy(XConfiguration.java:206) > ... > {noformat} > There's nothing we can do about the lock at the {{WebappClassLoader}}, but by > setting the {{javax.xml.parsers.DocumentBuilderFactory}} system property to > {{org.apache.xerces.jaxp.DocumentBuilderFactoryImpl}}, we can speed this up a > lot by getting rid of all of the searching that it's doing to find the > implementation. > See > https://docs.oracle.com/javase/7/docs/api/javax/xml/parsers/DocumentBuilderFactory.html#newInstance() > > and > https://www.databasesandlife.com/java-always-explicitly-specify-which-xml-parser-to-use/ > In our testing, we had a metric around creating a new {{JobClient}}, which > also calls {{DocumentBuilderFactory.newInstance}}, and it dropped from ~3min > max to ~2sec max (not an exact test of the savings here). And we also didn't > see so much blocking on this in the jstacks anymore. -- This message was sent by Atlassian JIRA (v6.3.15#6346)
[jira] [Updated] (OOZIE-2651) Set javax.xml.parsers.DocumentBuilderFactory sys prop to make XML handling faster
[ https://issues.apache.org/jira/browse/OOZIE-2651?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ] Robert Kanter updated OOZIE-2651: - Attachment: OOZIE-2651.002.patch I've just verified that this doesn't seem to be a problem for the Web UI with Jetty. I'm uploading a 002 patch that's rebased on the latest master, but is otherwise the same. > Set javax.xml.parsers.DocumentBuilderFactory sys prop to make XML handling > faster > - > > Key: OOZIE-2651 > URL: https://issues.apache.org/jira/browse/OOZIE-2651 > Project: Oozie > Issue Type: Improvement > Components: core >Affects Versions: trunk >Reporter: Robert Kanter >Assignee: Robert Kanter > Attachments: OOZIE-2651.001.patch, OOZIE-2651.002.patch > > > We noticed from some jstacks that Oozie was spending a lot of time looking > for XML related jars (we do a lot of XML parsing in Oozie and Hadoop code). > For instance, we'd see hundreds of threads blocked here > {noformat} > "pool-5-thread-57" prio=10 tid=0x7f9579923000 nid=0x6b7f waiting for > monitor entry [0x7f94225e3000] >java.lang.Thread.State: BLOCKED (on object monitor) > at > org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1559) > - waiting to lock <0x000500026148> (a > org.apache.catalina.loader.WebappClassLoader) > at > org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1526) > at > javax.xml.parsers.FactoryFinder.getProviderClass(FactoryFinder.java:117) > at javax.xml.parsers.FactoryFinder.newInstance(FactoryFinder.java:178) > at > javax.xml.parsers.FactoryFinder.findJarServiceProvider(FactoryFinder.java:333) > at javax.xml.parsers.FactoryFinder.find(FactoryFinder.java:255) > at > javax.xml.parsers.DocumentBuilderFactory.newInstance(DocumentBuilderFactory.java:121) > at > org.apache.hadoop.conf.Configuration.loadResource(Configuration.java:2526) > at > org.apache.hadoop.conf.Configuration.loadResources(Configuration.java:2503) > at > org.apache.hadoop.conf.Configuration.getProps(Configuration.java:2409) > - locked <0x0007eac5ea28> (a org.apache.hadoop.conf.Configuration) > at org.apache.hadoop.conf.Configuration.set(Configuration.java:1144) > at org.apache.hadoop.conf.Configuration.set(Configuration.java:1116) > at org.apache.oozie.util.XConfiguration.copy(XConfiguration.java:206) > ... > {noformat} > There's nothing we can do about the lock at the {{WebappClassLoader}}, but by > setting the {{javax.xml.parsers.DocumentBuilderFactory}} system property to > {{org.apache.xerces.jaxp.DocumentBuilderFactoryImpl}}, we can speed this up a > lot by getting rid of all of the searching that it's doing to find the > implementation. > See > https://docs.oracle.com/javase/7/docs/api/javax/xml/parsers/DocumentBuilderFactory.html#newInstance() > > and > https://www.databasesandlife.com/java-always-explicitly-specify-which-xml-parser-to-use/ > In our testing, we had a metric around creating a new {{JobClient}}, which > also calls {{DocumentBuilderFactory.newInstance}}, and it dropped from ~3min > max to ~2sec max (not an exact test of the savings here). And we also didn't > see so much blocking on this in the jstacks anymore. -- This message was sent by Atlassian JIRA (v6.3.15#6346)
[jira] [Updated] (OOZIE-2651) Set javax.xml.parsers.DocumentBuilderFactory sys prop to make XML handling faster
[ https://issues.apache.org/jira/browse/OOZIE-2651?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ] Robert Kanter updated OOZIE-2651: - Fix Version/s: (was: 4.3.0) > Set javax.xml.parsers.DocumentBuilderFactory sys prop to make XML handling > faster > - > > Key: OOZIE-2651 > URL: https://issues.apache.org/jira/browse/OOZIE-2651 > Project: Oozie > Issue Type: Improvement > Components: core >Affects Versions: trunk >Reporter: Robert Kanter >Assignee: Robert Kanter > Attachments: OOZIE-2651.001.patch > > > We noticed from some jstacks that Oozie was spending a lot of time looking > for XML related jars (we do a lot of XML parsing in Oozie and Hadoop code). > For instance, we'd see hundreds of threads blocked here > {noformat} > "pool-5-thread-57" prio=10 tid=0x7f9579923000 nid=0x6b7f waiting for > monitor entry [0x7f94225e3000] >java.lang.Thread.State: BLOCKED (on object monitor) > at > org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1559) > - waiting to lock <0x000500026148> (a > org.apache.catalina.loader.WebappClassLoader) > at > org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1526) > at > javax.xml.parsers.FactoryFinder.getProviderClass(FactoryFinder.java:117) > at javax.xml.parsers.FactoryFinder.newInstance(FactoryFinder.java:178) > at > javax.xml.parsers.FactoryFinder.findJarServiceProvider(FactoryFinder.java:333) > at javax.xml.parsers.FactoryFinder.find(FactoryFinder.java:255) > at > javax.xml.parsers.DocumentBuilderFactory.newInstance(DocumentBuilderFactory.java:121) > at > org.apache.hadoop.conf.Configuration.loadResource(Configuration.java:2526) > at > org.apache.hadoop.conf.Configuration.loadResources(Configuration.java:2503) > at > org.apache.hadoop.conf.Configuration.getProps(Configuration.java:2409) > - locked <0x0007eac5ea28> (a org.apache.hadoop.conf.Configuration) > at org.apache.hadoop.conf.Configuration.set(Configuration.java:1144) > at org.apache.hadoop.conf.Configuration.set(Configuration.java:1116) > at org.apache.oozie.util.XConfiguration.copy(XConfiguration.java:206) > ... > {noformat} > There's nothing we can do about the lock at the {{WebappClassLoader}}, but by > setting the {{javax.xml.parsers.DocumentBuilderFactory}} system property to > {{org.apache.xerces.jaxp.DocumentBuilderFactoryImpl}}, we can speed this up a > lot by getting rid of all of the searching that it's doing to find the > implementation. > See > https://docs.oracle.com/javase/7/docs/api/javax/xml/parsers/DocumentBuilderFactory.html#newInstance() > > and > https://www.databasesandlife.com/java-always-explicitly-specify-which-xml-parser-to-use/ > In our testing, we had a metric around creating a new {{JobClient}}, which > also calls {{DocumentBuilderFactory.newInstance}}, and it dropped from ~3min > max to ~2sec max (not an exact test of the savings here). And we also didn't > see so much blocking on this in the jstacks anymore. -- This message was sent by Atlassian JIRA (v6.3.4#6332)
[jira] [Updated] (OOZIE-2651) Set javax.xml.parsers.DocumentBuilderFactory sys prop to make XML handling faster
[ https://issues.apache.org/jira/browse/OOZIE-2651?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ] Robert Kanter updated OOZIE-2651: - Attachment: OOZIE-2651.001.patch The 001 patch adds a new config property, {{oozie.javax.xml.parsers.DocumentBuilderFactory}}, that lets you specify the Factory to use (default {{org.apache.xerces.jaxp.DocumentBuilderFactoryImpl}}). A blank/whitespace value tells Oozie not to set this. Unfortunately, I'll need to look into this some more because it breaks the Oozie Web UI (Tomcat can't find org.apache.xerces.jaxp.DocumentBuilderFactoryImpl). I probably need to add the Xerces jar to Tomcat somewhere. > Set javax.xml.parsers.DocumentBuilderFactory sys prop to make XML handling > faster > - > > Key: OOZIE-2651 > URL: https://issues.apache.org/jira/browse/OOZIE-2651 > Project: Oozie > Issue Type: Improvement > Components: core >Affects Versions: trunk >Reporter: Robert Kanter >Assignee: Robert Kanter > Fix For: 4.3.0 > > Attachments: OOZIE-2651.001.patch > > > We noticed from some jstacks that Oozie was spending a lot of time looking > for XML related jars (we do a lot of XML parsing in Oozie and Hadoop code). > For instance, we'd see hundreds of threads blocked here > {noformat} > "pool-5-thread-57" prio=10 tid=0x7f9579923000 nid=0x6b7f waiting for > monitor entry [0x7f94225e3000] >java.lang.Thread.State: BLOCKED (on object monitor) > at > org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1559) > - waiting to lock <0x000500026148> (a > org.apache.catalina.loader.WebappClassLoader) > at > org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1526) > at > javax.xml.parsers.FactoryFinder.getProviderClass(FactoryFinder.java:117) > at javax.xml.parsers.FactoryFinder.newInstance(FactoryFinder.java:178) > at > javax.xml.parsers.FactoryFinder.findJarServiceProvider(FactoryFinder.java:333) > at javax.xml.parsers.FactoryFinder.find(FactoryFinder.java:255) > at > javax.xml.parsers.DocumentBuilderFactory.newInstance(DocumentBuilderFactory.java:121) > at > org.apache.hadoop.conf.Configuration.loadResource(Configuration.java:2526) > at > org.apache.hadoop.conf.Configuration.loadResources(Configuration.java:2503) > at > org.apache.hadoop.conf.Configuration.getProps(Configuration.java:2409) > - locked <0x0007eac5ea28> (a org.apache.hadoop.conf.Configuration) > at org.apache.hadoop.conf.Configuration.set(Configuration.java:1144) > at org.apache.hadoop.conf.Configuration.set(Configuration.java:1116) > at org.apache.oozie.util.XConfiguration.copy(XConfiguration.java:206) > ... > {noformat} > There's nothing we can do about the lock at the {{WebappClassLoader}}, but by > setting the {{javax.xml.parsers.DocumentBuilderFactory}} system property to > {{org.apache.xerces.jaxp.DocumentBuilderFactoryImpl}}, we can speed this up a > lot by getting rid of all of the searching that it's doing to find the > implementation. > See > https://docs.oracle.com/javase/7/docs/api/javax/xml/parsers/DocumentBuilderFactory.html#newInstance() > > and > https://www.databasesandlife.com/java-always-explicitly-specify-which-xml-parser-to-use/ > In our testing, we had a metric around creating a new {{JobClient}}, which > also calls {{DocumentBuilderFactory.newInstance}}, and it dropped from ~3min > max to ~2sec max (not an exact test of the savings here). And we also didn't > see so much blocking on this in the jstacks anymore. -- This message was sent by Atlassian JIRA (v6.3.4#6332)
[jira] [Updated] (OOZIE-2651) Set javax.xml.parsers.DocumentBuilderFactory sys prop to make XML handling faster
[ https://issues.apache.org/jira/browse/OOZIE-2651?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ] Robert Kanter updated OOZIE-2651: - Description: We noticed from some jstacks that Oozie was spending a lot of time looking for XML related jars (we do a lot of XML parsing in Oozie and Hadoop code). For instance, we'd see hundreds of threads blocked here {noformat} "pool-5-thread-57" prio=10 tid=0x7f9579923000 nid=0x6b7f waiting for monitor entry [0x7f94225e3000] java.lang.Thread.State: BLOCKED (on object monitor) at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1559) - waiting to lock <0x000500026148> (a org.apache.catalina.loader.WebappClassLoader) at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1526) at javax.xml.parsers.FactoryFinder.getProviderClass(FactoryFinder.java:117) at javax.xml.parsers.FactoryFinder.newInstance(FactoryFinder.java:178) at javax.xml.parsers.FactoryFinder.findJarServiceProvider(FactoryFinder.java:333) at javax.xml.parsers.FactoryFinder.find(FactoryFinder.java:255) at javax.xml.parsers.DocumentBuilderFactory.newInstance(DocumentBuilderFactory.java:121) at org.apache.hadoop.conf.Configuration.loadResource(Configuration.java:2526) at org.apache.hadoop.conf.Configuration.loadResources(Configuration.java:2503) at org.apache.hadoop.conf.Configuration.getProps(Configuration.java:2409) - locked <0x0007eac5ea28> (a org.apache.hadoop.conf.Configuration) at org.apache.hadoop.conf.Configuration.set(Configuration.java:1144) at org.apache.hadoop.conf.Configuration.set(Configuration.java:1116) at org.apache.oozie.util.XConfiguration.copy(XConfiguration.java:206) ... {noformat} There's nothing we can do about the lock at the {{WebappClassLoader}}, but by setting the {{javax.xml.parsers.DocumentBuilderFactory}} system property to {{org.apache.xerces.jaxp.DocumentBuilderFactoryImpl}}, we can speed this up a lot by getting rid of all of the searching that it's doing to find the implementation. See https://docs.oracle.com/javase/7/docs/api/javax/xml/parsers/DocumentBuilderFactory.html#newInstance() and https://www.databasesandlife.com/java-always-explicitly-specify-which-xml-parser-to-use/ In our testing, we had a metric around creating a new {{JobClient}}, which also calls {{DocumentBuilderFactory.newInstance}}, and it dropped from ~3min max to ~2sec max (not an exact test of the savings here). And we also didn't see so much blocking on this in the jstacks anymore. was: We noticed from some jstacks that Oozie was spending a lot of time looking for XML related jars (we do a lot of XML parsing in Oozie and Hadoop code). For instance, we'd see hundreds of threads blocked here {noformat} "pool-5-thread-57" prio=10 tid=0x7f9579923000 nid=0x6b7f waiting for monitor entry [0x7f94225e3000] java.lang.Thread.State: BLOCKED (on object monitor) at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1559) - waiting to lock <0x000500026148> (a org.apache.catalina.loader.WebappClassLoader) at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1526) at javax.xml.parsers.FactoryFinder.getProviderClass(FactoryFinder.java:117) at javax.xml.parsers.FactoryFinder.newInstance(FactoryFinder.java:178) at javax.xml.parsers.FactoryFinder.findJarServiceProvider(FactoryFinder.java:333) at javax.xml.parsers.FactoryFinder.find(FactoryFinder.java:255) at javax.xml.parsers.DocumentBuilderFactory.newInstance(DocumentBuilderFactory.java:121) at org.apache.hadoop.conf.Configuration.loadResource(Configuration.java:2526) at org.apache.hadoop.conf.Configuration.loadResources(Configuration.java:2503) at org.apache.hadoop.conf.Configuration.getProps(Configuration.java:2409) - locked <0x0007eac5ea28> (a org.apache.hadoop.conf.Configuration) at org.apache.hadoop.conf.Configuration.set(Configuration.java:1144) at org.apache.hadoop.conf.Configuration.set(Configuration.java:1116) at org.apache.oozie.util.XConfiguration.copy(XConfiguration.java:206) ... {noformat} There's nothing we can do about the lock at the {{WebappClassLoader}}, but by setting the {{javax.xml.parsers.DocumentBuilderFactory}} system property to {{org.apache.xerces.jaxp.DocumentBuilderFactoryImpl}}, we can speed this up a lot by getting rid of all of the searching that it's doing to find the implementation. See https://docs.oracle.com/javase/7/docs/api/javax/xml/parsers/DocumentBuilderFactory.html#newInstance() and https://www.databasesandlife.com/java-always-explicitly-specify-which-xml-parser-to-use/ In our testing, we had a metric around creating a