Re: Limit connections in multi-context environment

[Bryan Larson]

I suppose the answer to this question could have been "Try it and find
out".  The requests indeed drop through, provided that the "block"
attribute is set to false.  The http status code was a 200 by default, but
this was straightforward to override.  Additional functionality, such as
redirecting to an error page, also works through subclassing the
SemaphoreValve class.  I'll add that the built-in JMX support is a huge
plus.  The custom attributes that I added to the valve were also exposed
through JMX without any hassle.

Bryan

On Tue, Oct 25, 2016 at 9:14 AM, Bryan Larson  wrote:

> Mark,
>
> I browsed the source code for the SemaphoreValve, and it appears that if a
> Semaphore cannot be acquired the request will effectively "drop through".
> Does that sound accurate?  What would I expect in terms of http status code
> for the requests that are filtered out?
>
> Thanks,
> Bryan
>
> On Tue, Oct 18, 2016 at 9:24 AM, Mark Thomas  wrote:
>
>> On 18/10/2016 15:04, Bryan Larson wrote:
>> > Good morning.  I recently posted a question on Stack Overflow that I
>> think
>> > would be better suited for this group.  Here is the question:
>> > http://stackoverflow.com/questions/40050063/tomcat-max-conne
>> ctions-on-a-per-context-basis.
>> > To summarize: Besides using multiple connectors in the server.xml file,
>> is
>> > there a way to limit max connections on a per context basis?
>>
>> http://tomcat.apache.org/tomcat-9.0-doc/config/valve.html#Semaphore_Valve
>>
>> Also available all the way back to Tomcat 6.
>>
>> > I read through the slides for Tomcat 9 here:
>> > http://events.linuxfoundation.org/sites/events/files/slides/
>> 2015-09-24-Tomcat-9.pdf.
>> > Wording such as "Better infrastructure for the cloud"
>>
>> Before I even looked at the slides I thought that sounded like JavaEE 8
>> waffle rather than a Tomcat feature. In the past there have been
>> mutterings about this having something to do with multi-tenancy without
>> any hard information on what that means for a Servlet container.
>>
>> > and "Tomcat 9 supports – multiple virtual hosts per connector (SNI)"
>>
>> That is just standard TLS virtual hosting.
>>
>> > lead me to believe
>> > there might be changes in Tomcat 9 that support this without extensive
>> > configuration changes.  Can this be confirmed?
>>
>> There are no Tomcat 9 specific changes to support this feature. (But you
>> don't need them.)
>>
>> Mark
>>
>>
>> -
>> To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org
>> For additional commands, e-mail: users-h...@tomcat.apache.org
>>
>>
>

Re: Limit connections in multi-context environment

[Bryan Larson]

Mark,

I browsed the source code for the SemaphoreValve, and it appears that if a
Semaphore cannot be acquired the request will effectively "drop through".
Does that sound accurate?  What would I expect in terms of http status code
for the requests that are filtered out?

Thanks,
Bryan

On Tue, Oct 18, 2016 at 9:24 AM, Mark Thomas  wrote:

> On 18/10/2016 15:04, Bryan Larson wrote:
> > Good morning.  I recently posted a question on Stack Overflow that I
> think
> > would be better suited for this group.  Here is the question:
> > http://stackoverflow.com/questions/40050063/tomcat-max-
> connections-on-a-per-context-basis.
> > To summarize: Besides using multiple connectors in the server.xml file,
> is
> > there a way to limit max connections on a per context basis?
>
> http://tomcat.apache.org/tomcat-9.0-doc/config/valve.html#Semaphore_Valve
>
> Also available all the way back to Tomcat 6.
>
> > I read through the slides for Tomcat 9 here:
> > http://events.linuxfoundation.org/sites/events/files/slides/
> 2015-09-24-Tomcat-9.pdf.
> > Wording such as "Better infrastructure for the cloud"
>
> Before I even looked at the slides I thought that sounded like JavaEE 8
> waffle rather than a Tomcat feature. In the past there have been
> mutterings about this having something to do with multi-tenancy without
> any hard information on what that means for a Servlet container.
>
> > and "Tomcat 9 supports – multiple virtual hosts per connector (SNI)"
>
> That is just standard TLS virtual hosting.
>
> > lead me to believe
> > there might be changes in Tomcat 9 that support this without extensive
> > configuration changes.  Can this be confirmed?
>
> There are no Tomcat 9 specific changes to support this feature. (But you
> don't need them.)
>
> Mark
>
>
> -
> To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org
> For additional commands, e-mail: users-h...@tomcat.apache.org
>
>

Re: Limit connections in multi-context environment

[Bryan Larson]

Mark,

Sorry for the delayed response.  I had a chance to test out the valve, and
my preliminary testing showed that this worked like a charm for my
application.  Thanks for your help.

Bryan

On Tue, Oct 18, 2016 at 9:24 AM, Mark Thomas  wrote:

> On 18/10/2016 15:04, Bryan Larson wrote:
> > Good morning.  I recently posted a question on Stack Overflow that I
> think
> > would be better suited for this group.  Here is the question:
> > http://stackoverflow.com/questions/40050063/tomcat-max-
> connections-on-a-per-context-basis.
> > To summarize: Besides using multiple connectors in the server.xml file,
> is
> > there a way to limit max connections on a per context basis?
>
> http://tomcat.apache.org/tomcat-9.0-doc/config/valve.html#Semaphore_Valve
>
> Also available all the way back to Tomcat 6.
>
> > I read through the slides for Tomcat 9 here:
> > http://events.linuxfoundation.org/sites/events/files/slides/
> 2015-09-24-Tomcat-9.pdf.
> > Wording such as "Better infrastructure for the cloud"
>
> Before I even looked at the slides I thought that sounded like JavaEE 8
> waffle rather than a Tomcat feature. In the past there have been
> mutterings about this having something to do with multi-tenancy without
> any hard information on what that means for a Servlet container.
>
> > and "Tomcat 9 supports – multiple virtual hosts per connector (SNI)"
>
> That is just standard TLS virtual hosting.
>
> > lead me to believe
> > there might be changes in Tomcat 9 that support this without extensive
> > configuration changes.  Can this be confirmed?
>
> There are no Tomcat 9 specific changes to support this feature. (But you
> don't need them.)
>
> Mark
>
>
> -
> To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org
> For additional commands, e-mail: users-h...@tomcat.apache.org
>
>

Re: Limit connections in multi-context environment

[Mark Thomas]

On 18/10/2016 15:04, Bryan Larson wrote:
> Good morning.  I recently posted a question on Stack Overflow that I think
> would be better suited for this group.  Here is the question:
> http://stackoverflow.com/questions/40050063/tomcat-max-connections-on-a-per-context-basis.
> To summarize: Besides using multiple connectors in the server.xml file, is
> there a way to limit max connections on a per context basis?

http://tomcat.apache.org/tomcat-9.0-doc/config/valve.html#Semaphore_Valve

Also available all the way back to Tomcat 6.

> I read through the slides for Tomcat 9 here:
> http://events.linuxfoundation.org/sites/events/files/slides/2015-09-24-Tomcat-9.pdf.
> Wording such as "Better infrastructure for the cloud"

Before I even looked at the slides I thought that sounded like JavaEE 8
waffle rather than a Tomcat feature. In the past there have been
mutterings about this having something to do with multi-tenancy without
any hard information on what that means for a Servlet container.

> and "Tomcat 9 supports – multiple virtual hosts per connector (SNI)"

That is just standard TLS virtual hosting.

> lead me to believe
> there might be changes in Tomcat 9 that support this without extensive
> configuration changes.  Can this be confirmed?

There are no Tomcat 9 specific changes to support this feature. (But you
don't need them.)

Mark


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Limit connections in multi-context environment

[Bryan Larson]

Good morning.  I recently posted a question on Stack Overflow that I think
would be better suited for this group.  Here is the question:
http://stackoverflow.com/questions/40050063/tomcat-max-connections-on-a-per-context-basis.
To summarize: Besides using multiple connectors in the server.xml file, is
there a way to limit max connections on a per context basis?

I read through the slides for Tomcat 9 here:
http://events.linuxfoundation.org/sites/events/files/slides/2015-09-24-Tomcat-9.pdf.
Wording such as "Better infrastructure for the cloud" and "Tomcat 9
supports – multiple virtual hosts per connector (SNI)" lead me to believe
there might be changes in Tomcat 9 that support this without extensive
configuration changes.  Can this be confirmed?

Thanks,
Bryan