A couple thoughts: 1) Looking at wildfly-init-redhat.sh at least, I don't see how that check is actually testing for successful startup. It looks like it's just trying to delay start() returning for a while, max 30 secs. So, what purpose is this fulfilling?

2) How does other software solve this problem? If it's solving a valid problem, it seems like there would be a typical solution.

On 6/9/15 8:59 AM, Chao Wang wrote: > Hi all, > > The Wildfly start-up as service scripts wildfly-init-redhat.sh and > wildfly-init-debian.sh currently depend on a grep action of key message > 'WFLYSRV0025:' in console log to determinate whether service start is > successful. The log message indication is accurate, however, it's not > that robust since user can always remove console handler from logging > subsystem. I have opened a WFCORE enhancement jira > https://issues.jboss.org/browse/WFCORE-747 for it. > > For the moment, I have tried three options, they're all not that perfect > to implement > > 1. Stay with exact log message, users need to define their jboss log > directory such as $JBOSS_HOME/standalone/log/server.log for standalone > and $JBOSS_HOME/domain/log/host-controller.log for domain instead of > searching in console log. This is more like another workaround since it > is also volatile once we update log message in future release.(EAP has > 'JBAS015874:') > > 2. Use service pid, this is not precise because a long start-up can > crash in the last second. It needs to wait a suitable seconds before > checking pid existence. and still it can not avoid fake success in rare > case just before timeout. > > 3. Use read-attribute server-state through CLI connection as I did in > Pull Request on Jira. This is declined as it is possible that > authentication is required before connection. In such case, any non > encrypted password is not advised in configuration files. > > Therefore, I would like to listen for your opinions for them. Any other > suggestion is certainly welcomed in mail or on jira. > > Best regards, > > Chao > > > _______________________________________________ > wildfly-dev mailing list > wildfly-dev(a)lists.jboss.org > https://lists.jboss.org/mailman/listinfo/wildfly-dev >

On Jun 10, 2015, at 11:46 AM, Brian Stansberry <brian.stansberry(a)redhat.com&gt; wrote: So, what purpose is this fulfilling? 2) How does other software solve this problem? If it's solving a valid problem, it seems like there would be a typical solution.

Thanks for your reply. Please see in-line below On 06/11/2015 12:44 AM, Brian Stansberry wrote: > A couple thoughts: > > 1) Looking at wildfly-init-redhat.sh at least, I don't see how that > check is actually testing for successful startup. It looks like it's > just trying to delay start() returning for a while, max 30 secs. > > So, what purpose is this fulfilling? My bad about issue background. It's actually an case in EAP 6 (not yet in wildfly). EAP 6.x script has launched state like: https://github.com/jbossas/jboss-eap/blob/6.4.x/build/src/main/resources/... (not in wildfly's script). Also, console log handler has been removed only in EAP full-ha mode long time ago due to performance concern.(wildfly keeps it for the moment). This leads to issue in bz1224170 <https://bugzilla.redhat.com/show_bug.cgi?id=1224170>;. That's why I try to seek an better option than current behavior from wildfly. > > 2) How does other software solve this problem? If it's solving a valid > problem, it seems like there would be a typical solution. I have checked some other application servers, most of them let users themselves to write a script to run as service for their OS. Geronimo does provide a script, Although I did damage to its configuration file to make a fatal error, terminal output still displays "Server started". In fact, process does not event exist and detail error can be seen in log file. > On 6/9/15 8:59 AM, Chao Wang wrote: >> Hi all, >> >> The Wildfly start-up as service scripts wildfly-init-redhat.sh and >> wildfly-init-debian.sh currently depend on a grep action of key message >> 'WFLYSRV0025:' in console log to determinate whether service start is >> successful. The log message indication is accurate, however, it's not >> that robust since user can always remove console handler from logging >> subsystem. I have opened a WFCORE enhancement jira >> https://issues.jboss.org/browse/WFCORE-747 for it. >> >> For the moment, I have tried three options, they're all not that perfect >> to implement >> >> 1. Stay with exact log message, users need to define their jboss log >> directory such as $JBOSS_HOME/standalone/log/server.log for standalone >> and $JBOSS_HOME/domain/log/host-controller.log for domain instead of >> searching in console log. This is more like another workaround since it >> is also volatile once we update log message in future release.(EAP has >> 'JBAS015874:') >> >> 2. Use service pid, this is not precise because a long start-up can >> crash in the last second. It needs to wait a suitable seconds before >> checking pid existence. and still it can not avoid fake success in rare >> case just before timeout. >> >> 3. Use read-attribute server-state through CLI connection as I did in >> Pull Request on Jira. This is declined as it is possible that >> authentication is required before connection. In such case, any non >> encrypted password is not advised in configuration files. >> >> Therefore, I would like to listen for your opinions for them. Any other >> suggestion is certainly welcomed in mail or on jira. >> >> Best regards, >> >> Chao >> >> >> _______________________________________________ >> wildfly-dev mailing list >> wildfly-dev(a)lists.jboss.org >> https://lists.jboss.org/mailman/listinfo/wildfly-dev >> > [1] https://bugzilla.redhat.com/show_bug.cgi?id=1224170 -- Chao Wang Software Engineer JBoss by Red Hat _______________________________________________ wildfly-dev mailing list wildfly-dev(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/wildfly-dev

On Jun 12, 2015, at 11:32 AM, Jorge Solórzano <jorsol(a)gmail.com&gt; wrote: It has been considered the use of Java Service Wrapper[1]? it depends on native binaries but almost all platforms are supported. [1] http://wrapper.tanukisoftware.com <http://wrapper.tanukisoftware.com/> Jorge Solórzano http://www.jorsol.com <http://www.jorsol.com/> On Fri, Jun 12, 2015 at 8:27 AM, Brian Stansberry <brian.stansberry(a)redhat.com <mailto:brian.stansberry@redhat.com>> wrote: How does EAP 5 deal with this? IIRC disabling console logging is not something new in EAP 6. On 6/11/15 6:29 PM, Chao Wang wrote: > Thanks for your reply. Please see in-line below > > On 06/11/2015 12:44 AM, Brian Stansberry wrote: >> A couple thoughts: >> >> 1) Looking at wildfly-init-redhat.sh at least, I don't see how that >> check is actually testing for successful startup. It looks like it's >> just trying to delay start() returning for a while, max 30 secs. >> >> So, what purpose is this fulfilling? > My bad about issue background. It's actually an case in EAP 6 (not yet > in wildfly). EAP 6.x script has launched state like: > https://github.com/jbossas/jboss-eap/blob/6.4.x/build/src/main/resources/... <https://github.com/jbossas/jboss-eap/blob/6.4.x/build/src/main/resources/... > (not in wildfly's script). Also, console log handler has been removed > only in EAP full-ha mode long time ago due to performance > concern.(wildfly keeps it for the moment). This leads to issue in > bz1224170 <https://bugzilla.redhat.com/show_bug.cgi?id=1224170 <https://bugzilla.redhat.com/show_bug.cgi?id=1224170>>;. > That's why I try to seek an better option than current behavior from > wildfly. >> >> 2) How does other software solve this problem? If it's solving a valid >> problem, it seems like there would be a typical solution. > I have checked some other application servers, most of them let users > themselves to write a script to run as service for their OS. Geronimo > does provide a script, Although I did damage to its configuration file > to make a fatal error, terminal output still displays "Server started". > In fact, process does not event exist and detail error can be seen in > log file. >> On 6/9/15 8:59 AM, Chao Wang wrote: >>> Hi all, >>> >>> The Wildfly start-up as service scripts wildfly-init-redhat.sh and >>> wildfly-init-debian.sh currently depend on a grep action of key message >>> 'WFLYSRV0025:' in console log to determinate whether service start is >>> successful. The log message indication is accurate, however, it's not >>> that robust since user can always remove console handler from logging >>> subsystem. I have opened a WFCORE enhancement jira >>> https://issues.jboss.org/browse/WFCORE-747 <https://issues.jboss.org/browse/WFCORE-747> for it. >>> >>> For the moment, I have tried three options, they're all not that perfect >>> to implement >>> >>> 1. Stay with exact log message, users need to define their jboss log >>> directory such as $JBOSS_HOME/standalone/log/server.log for standalone >>> and $JBOSS_HOME/domain/log/host-controller.log for domain instead of >>> searching in console log. This is more like another workaround since it >>> is also volatile once we update log message in future release.(EAP has >>> 'JBAS015874:') >>> >>> 2. Use service pid, this is not precise because a long start-up can >>> crash in the last second. It needs to wait a suitable seconds before >>> checking pid existence. and still it can not avoid fake success in rare >>> case just before timeout. >>> >>> 3. Use read-attribute server-state through CLI connection as I did in >>> Pull Request on Jira. This is declined as it is possible that >>> authentication is required before connection. In such case, any non >>> encrypted password is not advised in configuration files. >>> >>> Therefore, I would like to listen for your opinions for them. Any other >>> suggestion is certainly welcomed in mail or on jira. >>> >>> Best regards, >>> >>> Chao >>> >>> >>> _______________________________________________ >>> wildfly-dev mailing list >>> wildfly-dev(a)lists.jboss.org <mailto:wildfly-dev@lists.jboss.org> >>> https://lists.jboss.org/mailman/listinfo/wildfly-dev <https://lists.jboss.org/mailman/listinfo/wildfly-dev> >>> >> > > [1] https://bugzilla.redhat.com/show_bug.cgi?id=1224170 <https://bugzilla.redhat.com/show_bug.cgi?id=1224170> > > -- > Chao Wang > Software Engineer > JBoss by Red Hat > > > > _______________________________________________ > wildfly-dev mailing list > wildfly-dev(a)lists.jboss.org <mailto:wildfly-dev@lists.jboss.org> > https://lists.jboss.org/mailman/listinfo/wildfly-dev <https://lists.jboss.org/mailman/listinfo/wildfly-dev> > -- Brian Stansberry Senior Principal Software Engineer JBoss by Red Hat _______________________________________________ wildfly-dev mailing list wildfly-dev(a)lists.jboss.org <mailto:wildfly-dev@lists.jboss.org> https://lists.jboss.org/mailman/listinfo/wildfly-dev <https://lists.jboss.org/mailman/listinfo/wildfly-dev> _______________________________________________ wildfly-dev mailing list wildfly-dev(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/wildfly-dev

I think there is no easy fix, we can assume for example that after 3 seconds that the PID exists then the process is up and return OK, but if the process stops latter, it will be a fake start. I know that we should not rely on read the log as James stated, but until we can figure out a better aproach this is my proposal, I can modify wildfly-init-debian.sh to have this behavior 1. Add to logging subsystem to standalone*.xml: <logger category="org.jboss.as <http://org.jboss.as>"> <level name="INFO"/> </logger> 2. Remove JBOSS_CONSOLE_LOG and read JBOSS_LOG_DIR 3. If standalone read "$JBOSS_LOG_DIR/server.log" if domain read "$JBOSS_LOG_DIR/host-controller.log" to find WFLYSRV0025 or the string used for EAP... this is probably volatile but it's not changed frequently, in fact it has been changed only once. 4. Always check the status of pid (if dies return immediately). 5. If server.log is not found, deactivated or not print the correct output there are two choices: a. On wait timeout, send a warning about an unknow status (this is how works right now). b. On wait timeout, just check if PID is still up and return OK, otherwise FAILURE. I believe this approach avoids the problem of console log... ​ ​ Best regards, Jorge Solórzano http://www.jorsol.com On Thu, Jun 11, 2015 at 5:29 PM, Chao Wang <chaowan(a)redhat.com <mailto:chaowan@redhat.com>> wrote: Thanks for your reply. Please see in-line below On 06/11/2015 12:44 AM, Brian Stansberry wrote: > A couple thoughts: > > 1) Looking at wildfly-init-redhat.sh at least, I don't see how that > check is actually testing for successful startup. It looks like it's > just trying to delay start() returning for a while, max 30 secs. > > So, what purpose is this fulfilling? My bad about issue background. It's actually an case in EAP 6 (not yet in wildfly). EAP 6.x script has launched state like: https://github.com/jbossas/jboss-eap/blob/6.4.x/build/src/main/resources/... (not in wildfly's script). Also, console log handler has been removed only in EAP full-ha mode long time ago due to performance concern.(wildfly keeps it for the moment). This leads to issue in bz1224170 <https://bugzilla.redhat.com/show_bug.cgi?id=1224170>;. That's why I try to seek an better option than current behavior from wildfly. > 2) How does other software solve this problem? If it's solving a valid > problem, it seems like there would be a typical solution. I have checked some other application servers, most of them let users themselves to write a script to run as service for their OS. Geronimo does provide a script, Although I did damage to its configuration file to make a fatal error, terminal output still displays "Server started". In fact, process does not event exist and detail error can be seen in log file. > On 6/9/15 8:59 AM, Chao Wang wrote: >> Hi all, >> >> The Wildfly start-up as service scripts wildfly-init-redhat.sh and >> wildfly-init-debian.sh currently depend on a grep action of key message >> 'WFLYSRV0025:' in console log to determinate whether service start is >> successful. The log message indication is accurate, however, it's not >> that robust since user can always remove console handler from logging >> subsystem. I have opened a WFCORE enhancement jira >> https://issues.jboss.org/browse/WFCORE-747 for it. >> >> For the moment, I have tried three options, they're all not that perfect >> to implement >> >> 1. Stay with exact log message, users need to define their jboss log >> directory such as $JBOSS_HOME/standalone/log/server.log for standalone >> and $JBOSS_HOME/domain/log/host-controller.log for domain instead of >> searching in console log. This is more like another workaround since it >> is also volatile once we update log message in future release.(EAP has >> 'JBAS015874:') >> >> 2. Use service pid, this is not precise because a long start-up can >> crash in the last second. It needs to wait a suitable seconds before >> checking pid existence. and still it can not avoid fake success in rare >> case just before timeout. >> >> 3. Use read-attribute server-state through CLI connection as I did in >> Pull Request on Jira. This is declined as it is possible that >> authentication is required before connection. In such case, any non >> encrypted password is not advised in configuration files. >> >> Therefore, I would like to listen for your opinions for them. Any other >> suggestion is certainly welcomed in mail or on jira. >> ​​ >> >> Best regards, >> >> Chao >> >> >> _______________________________________________ >> wildfly-dev mailing list >> wildfly-dev(a)lists.jboss.org <mailto:wildfly-dev@lists.jboss.org> >> https://lists.jboss.org/mailman/listinfo/wildfly-dev >> [1] https://bugzilla.redhat.com/show_bug.cgi?id=1224170 -- Chao Wang Software Engineer JBoss by Red Hat _______________________________________________ wildfly-dev mailing list wildfly-dev(a)lists.jboss.org <mailto:wildfly-dev@lists.jboss.org> https://lists.jboss.org/mailman/listinfo/wildfly-dev _______________________________________________ wildfly-dev mailing list wildfly-dev(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/wildfly-dev

On Jun 12, 2015, at 12:02 PM, Jorge Solórzano <jorsol(a)gmail.com&gt; wrote: On Fri, Jun 12, 2015 at 10:51 AM, Jason Greene <jason.greene(a)redhat.com <mailto:jason.greene@redhat.com>> wrote: That just monitors console output. ​Not exacly, there are various modes of integration, posibly the most complex but flexible aproach is to use a listener[1] so it can be adapted properly to what we want. [1] http://wrapper.tanukisoftware.com/doc/english/integrate-listener.html <http://wrapper.tanukisoftware.com/doc/english/integrate-listener.html>​ > On Jun 12, 2015, at 11:32 AM, Jorge Solórzano <jorsol(a)gmail.com <mailto:jorsol@gmail.com>> wrote: > > It has been considered the use of Java Service Wrapper[1]? it depends on native binaries but almost all platforms are supported. > > [1] http://wrapper.tanukisoftware.com <http://wrapper.tanukisoftware.com/> > > > Jorge Solórzano > http://www.jorsol.com <http://www.jorsol.com/> > On Fri, Jun 12, 2015 at 8:27 AM, Brian Stansberry <brian.stansberry(a)redhat.com <mailto:brian.stansberry@redhat.com>> wrote: > How does EAP 5 deal with this? IIRC disabling console logging is not > something new in EAP 6. > > On 6/11/15 6:29 PM, Chao Wang wrote: > > Thanks for your reply. Please see in-line below > > > > On 06/11/2015 12:44 AM, Brian Stansberry wrote: > >> A couple thoughts: > >> > >> 1) Looking at wildfly-init-redhat.sh at least, I don't see how that > >> check is actually testing for successful startup. It looks like it's > >> just trying to delay start() returning for a while, max 30 secs. > >> > >> So, what purpose is this fulfilling? > > My bad about issue background. It's actually an case in EAP 6 (not yet > > in wildfly). EAP 6.x script has launched state like: > > https://github.com/jbossas/jboss-eap/blob/6.4.x/build/src/main/resources/... <https://github.com/jbossas/jboss-eap/blob/6.4.x/build/src/main/resources/... > > (not in wildfly's script). Also, console log handler has been removed > > only in EAP full-ha mode long time ago due to performance > > concern.(wildfly keeps it for the moment). This leads to issue in > > bz1224170 <https://bugzilla.redhat.com/show_bug.cgi?id=1224170 <https://bugzilla.redhat.com/show_bug.cgi?id=1224170>>;. > > That's why I try to seek an better option than current behavior from > > wildfly. > >> > >> 2) How does other software solve this problem? If it's solving a valid > >> problem, it seems like there would be a typical solution. > > I have checked some other application servers, most of them let users > > themselves to write a script to run as service for their OS. Geronimo > > does provide a script, Although I did damage to its configuration file > > to make a fatal error, terminal output still displays "Server started". > > In fact, process does not event exist and detail error can be seen in > > log file. > >> On 6/9/15 8:59 AM, Chao Wang wrote: > >>> Hi all, > >>> > >>> The Wildfly start-up as service scripts wildfly-init-redhat.sh and > >>> wildfly-init-debian.sh currently depend on a grep action of key message > >>> 'WFLYSRV0025:' in console log to determinate whether service start is > >>> successful. The log message indication is accurate, however, it's not > >>> that robust since user can always remove console handler from logging > >>> subsystem. I have opened a WFCORE enhancement jira > >>> https://issues.jboss.org/browse/WFCORE-747 <https://issues.jboss.org/browse/WFCORE-747> for it. > >>> > >>> For the moment, I have tried three options, they're all not that perfect > >>> to implement > >>> > >>> 1. Stay with exact log message, users need to define their jboss log > >>> directory such as $JBOSS_HOME/standalone/log/server.log for standalone > >>> and $JBOSS_HOME/domain/log/host-controller.log for domain instead of > >>> searching in console log. This is more like another workaround since it > >>> is also volatile once we update log message in future release.(EAP has > >>> 'JBAS015874:') > >>> > >>> 2. Use service pid, this is not precise because a long start-up can > >>> crash in the last second. It needs to wait a suitable seconds before > >>> checking pid existence. and still it can not avoid fake success in rare > >>> case just before timeout. > >>> > >>> 3. Use read-attribute server-state through CLI connection as I did in > >>> Pull Request on Jira. This is declined as it is possible that > >>> authentication is required before connection. In such case, any non > >>> encrypted password is not advised in configuration files. > >>> > >>> Therefore, I would like to listen for your opinions for them. Any other > >>> suggestion is certainly welcomed in mail or on jira. > >>> > >>> Best regards, > >>> > >>> Chao > >>> > >>> > >>> _______________________________________________ > >>> wildfly-dev mailing list > >>> wildfly-dev(a)lists.jboss.org <mailto:wildfly-dev@lists.jboss.org> > >>> https://lists.jboss.org/mailman/listinfo/wildfly-dev <https://lists.jboss.org/mailman/listinfo/wildfly-dev> > >>> > >> > > > > [1] https://bugzilla.redhat.com/show_bug.cgi?id=1224170 <https://bugzilla.redhat.com/show_bug.cgi?id=1224170> > > > > -- > > Chao Wang > > Software Engineer > > JBoss by Red Hat > > > > > > > > _______________________________________________ > > wildfly-dev mailing list > > wildfly-dev(a)lists.jboss.org <mailto:wildfly-dev@lists.jboss.org> > > https://lists.jboss.org/mailman/listinfo/wildfly-dev <https://lists.jboss.org/mailman/listinfo/wildfly-dev> > > > > > -- > Brian Stansberry > Senior Principal Software Engineer > JBoss by Red Hat > _______________________________________________ > wildfly-dev mailing list > wildfly-dev(a)lists.jboss.org <mailto:wildfly-dev@lists.jboss.org> > https://lists.jboss.org/mailman/listinfo/wildfly-dev <https://lists.jboss.org/mailman/listinfo/wildfly-dev> > > _______________________________________________ > wildfly-dev mailing list > wildfly-dev(a)lists.jboss.org <mailto:wildfly-dev@lists.jboss.org> > https://lists.jboss.org/mailman/listinfo/wildfly-dev <https://lists.jboss.org/mailman/listinfo/wildfly-dev> -- Jason T. Greene WildFly Lead / JBoss EAP Platform Architect JBoss, a division of Red Hat

How does EAP 5 deal with this? IIRC disabling console logging is not something new in EAP 6.

On 6/11/15 6:29 PM, Chao Wang wrote: > Thanks for your reply. Please see in-line below > > On 06/11/2015 12:44 AM, Brian Stansberry wrote: >> A couple thoughts: >> >> 1) Looking at wildfly-init-redhat.sh at least, I don't see how that >> check is actually testing for successful startup. It looks like it's >> just trying to delay start() returning for a while, max 30 secs. >> >> So, what purpose is this fulfilling? > My bad about issue background. It's actually an case in EAP 6 (not yet > in wildfly). EAP 6.x script has launched state like: > https://github.com/jbossas/jboss-eap/blob/6.4.x/build/src/main/resources/... > (not in wildfly's script). Also, console log handler has been removed > only in EAP full-ha mode long time ago due to performance > concern.(wildfly keeps it for the moment). This leads to issue in > bz1224170 <https://bugzilla.redhat.com/show_bug.cgi?id=1224170>;. > That's why I try to seek an better option than current behavior from > wildfly. >> 2) How does other software solve this problem? If it's solving a valid >> problem, it seems like there would be a typical solution. > I have checked some other application servers, most of them let users > themselves to write a script to run as service for their OS. Geronimo > does provide a script, Although I did damage to its configuration file > to make a fatal error, terminal output still displays "Server started". > In fact, process does not event exist and detail error can be seen in > log file. >> On 6/9/15 8:59 AM, Chao Wang wrote: >>> Hi all, >>> >>> The Wildfly start-up as service scripts wildfly-init-redhat.sh and >>> wildfly-init-debian.sh currently depend on a grep action of key message >>> 'WFLYSRV0025:' in console log to determinate whether service start is >>> successful. The log message indication is accurate, however, it's not >>> that robust since user can always remove console handler from logging >>> subsystem. I have opened a WFCORE enhancement jira >>> https://issues.jboss.org/browse/WFCORE-747 for it. >>> >>> For the moment, I have tried three options, they're all not that perfect >>> to implement >>> >>> 1. Stay with exact log message, users need to define their jboss log >>> directory such as $JBOSS_HOME/standalone/log/server.log for standalone >>> and $JBOSS_HOME/domain/log/host-controller.log for domain instead of >>> searching in console log. This is more like another workaround since it >>> is also volatile once we update log message in future release.(EAP has >>> 'JBAS015874:') >>> >>> 2. Use service pid, this is not precise because a long start-up can >>> crash in the last second. It needs to wait a suitable seconds before >>> checking pid existence. and still it can not avoid fake success in rare >>> case just before timeout. >>> >>> 3. Use read-attribute server-state through CLI connection as I did in >>> Pull Request on Jira. This is declined as it is possible that >>> authentication is required before connection. In such case, any non >>> encrypted password is not advised in configuration files. >>> >>> Therefore, I would like to listen for your opinions for them. Any other >>> suggestion is certainly welcomed in mail or on jira. >>> >>> Best regards, >>> >>> Chao >>> >>> >>> _______________________________________________ >>> wildfly-dev mailing list >>> wildfly-dev(a)lists.jboss.org >>> https://lists.jboss.org/mailman/listinfo/wildfly-dev >>> > [1] https://bugzilla.redhat.com/show_bug.cgi?id=1224170 > > -- > Chao Wang > Software Engineer > JBoss by Red Hat > > > > _______________________________________________ > wildfly-dev mailing list > wildfly-dev(a)lists.jboss.org > https://lists.jboss.org/mailman/listinfo/wildfly-dev >

This is yet another good use case for an idea I proposed at the last couple developer meeting: the idea of configurable "availability" services, where you add a configuration which says "when these components and/or configured services are available, perform this action" where the action might be to notify a load balancer, perform a notification to humans, or even drop a file to the filesystem (which would be directly useful to this use case). Note (in case someone thinks this is a great idea and runs out to implement it right away) that when I say "configured services" I do not mean MSC service names; more like management capabilities where you have a constrained namespace and each subsystem can contribute services to this category.

Also note that Java 9 adds limited support for signalling unrelated processes, though at the moment on UNIX the signals are basically limited to TERM and KILL. On 06/12/2015 07:06 AM, Jason T. Greene wrote: >> On Jun 10, 2015, at 11:46 AM, Brian Stansberry <brian.stansberry(a)redhat.com&gt; wrote: >> >> So, what purpose is this fulfilling? >> >> 2) How does other software solve this problem? If it's solving a valid >> problem, it seems like there would be a typical solution. > The classic UNIX solution is that the daemon forks and returns, dropping a PID file of its child to disk, after it is done initializing and exits with an error code when there is a problem. > > Systemd added other approaches, where a daemon can signal systemd directly, or it can use dbus to send a message. > > The former can't be done efficiently in Java because it doesn't have a pure fork(), only an exec. Although it would be possible to emulate with an exec with an unacceptable hit to boot time. The latter options are too Linux specific. > > I think the best solution would be for us to add a signaling mechanism specifically for this purpose. We could use sun.misc.Signal (potentially an issue on Java 9), or we could exec the kill command to signal a process. > > We could also use a specially status file (e.g standalone.sh --start-status-file=blah) for a script to monitor. > > Thoughts? > _______________________________________________ > wildfly-dev mailing list > wildfly-dev(a)lists.jboss.org > https://lists.jboss.org/mailman/listinfo/wildfly-dev >

On 06/12/2015 02:57 PM, David M. Lloyd wrote: > This is yet another good use case for an idea I proposed at the last > couple developer meeting: the idea of configurable "availability" > services, where you add a configuration which says "when these > components and/or configured services are available, perform this > action" where the action might be to notify a load balancer, perform a > notification to humans, or even drop a file to the filesystem (which > would be directly useful to this use case). > > Note (in case someone thinks this is a great idea and runs out to > implement it right away) that when I say "configured services" I do not > mean MSC service names; more like management capabilities where you have > a constrained namespace and each subsystem can contribute services to > this category. Wouldn't implementing a MSC service with dependencies be just the quick fix that covers the use case? :-)

Carlo > > Also note that Java 9 adds limited support for signalling unrelated > processes, though at the moment on UNIX the signals are basically > limited to TERM and KILL. > > On 06/12/2015 07:06 AM, Jason T. Greene wrote: >>> On Jun 10, 2015, at 11:46 AM, Brian Stansberry >>> <brian.stansberry(a)redhat.com&gt; wrote: >>> >>> So, what purpose is this fulfilling? >>> >>> 2) How does other software solve this problem? If it's solving a valid >>> problem, it seems like there would be a typical solution. >> The classic UNIX solution is that the daemon forks and returns, >> dropping a PID file of its child to disk, after it is done >> initializing and exits with an error code when there is a problem. >> >> Systemd added other approaches, where a daemon can signal systemd >> directly, or it can use dbus to send a message. >> >> The former can't be done efficiently in Java because it doesn't have >> a pure fork(), only an exec. Although it would be possible to emulate >> with an exec with an unacceptable hit to boot time. The latter >> options are too Linux specific. >> >> I think the best solution would be for us to add a signaling >> mechanism specifically for this purpose. We could use sun.misc.Signal >> (potentially an issue on Java 9), or we could exec the kill command >> to signal a process. >> >> We could also use a specially status file (e.g standalone.sh >> --start-status-file=blah) for a script to monitor. >> >> Thoughts? >> _______________________________________________ >> wildfly-dev mailing list >> wildfly-dev(a)lists.jboss.org >> https://lists.jboss.org/mailman/listinfo/wildfly-dev >>