-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 Frederik,
On 3/26/14, 9:32 PM, Frederik Nosi wrote: > My scenario is Apache httpd + mod_jk + N Tomcat's in. The default > behaviour of load balanced workers in mod_jk in my testing is that > when a client requests a page (GET / POST / Whatever), the LB > worker tries the request to every ajp worker. This in contrast with > what i read here: > > > http://people.apache.org/~mturk/docs/article/ftwai.html > <http://people.apache.org/%7Emturk/docs/article/ftwai.html> > > Expecially this part: > > > When having multiple nodes in a cluster you can improve your > application availability by implementing failover. The failover > means that if the particular elected node can not fulfill the > request the another node will be selected automatically. In case of > three nodes you are actually doubling your application > availability. The application response time will be slower during > failover, but none of your users will be rejected. Inside the > mod_jk configuration there is a special configuration parameter > called worker.retries that has default value of 3, but that needs > to be adjusted to the actual number of nodes in the cluster. > > ... worker.list=lbworker worker.lbworker.type=lb # Adjust to the > number of workers worker.retries=4 > worker.lbworker.balance_workers=node1,node2,node3,node4 If you add > more then three workers to the load balancer adjust the retries > parameter to reflect that number. It will ensure that even in the > worse case scenario the request gets served if there is a single > operable node. > > From that it seems that the "retries" parameter in a load balancer > worker context should mean the number of real (AJP) workers to > try. (what i need indeed) but in my testing, that LB worker > parameter is the number of times that all the AJP workers that are > part of the LB worker get a round retry. In eg, having a LB worker > with 4 AJP workers, setting LB Worker's retries = 2, the behaviour > i see is that the AJP workers get called this way: > > AJP1 -> timeout [...] AJP4 -> timeout > > ===> repeat again (retries == 2) > > AJP1 -> timeout [...] AJP4 -> timeout > > --> LB sends an error to the client. > > > > Now from the online documentation the meaning of that parameter in > a load balancer worker context is'nt that clear, but from the link > i provided seems it was exactly what i needed, not the number of > retries to all AJP workers, but the number of single AJP workers to > try.. > > If that is not correct i can fill a bug report. If instead it's by > design, the attached patch adds a new parameter, "lb_retries", that > does what i need. Of course it's a bit rough, but works. > > Any comments? Am I getting stuff wrong? I'm bumping this because I can see Rainer has fixed a bunch of things in mod_jk over the last few days. Perhaps he's getting ready to do a release or something. - -chris -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 Comment: GPGTools - http://gpgtools.org Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iQIcBAEBCAAGBQJTOzvQAAoJEBzwKT+lPKRY6uEQAISOkIa3VwSlhVEu/JPuhqDD SHN7/hui6l/0oj2chPRr1YWs0XO8yuP8afgzlfuJhWQ5fNeVshDliYijYusKZPSx 666iVZ4NqVF8zTYo7Y6LE7gJJS8LrZUnD/nEF3ngCWGp5V6KzbQkB2haQBeFFRX2 bK2xcPFAC/hhT4QmkSkyCb8KaqyGtgIZDXToiQlA1oWRkleRip8yU+JwZEQXUz8v MNhRtG5hUiX5z6wJh7OVTRu421mwmfZav4SUNxvjN71UnvoiRST4H3qrQGeD6fHh 2bKq4ot+olZ7T0Wo4fd6NqRzn/7fwRfp9U6OIrwe5umjaWzYd99o/iTm31hcFJFz f6d1A0A5uqZaDT2+o8y01qSbdIWDYZFKRv7KZuX1/+6WXp6h7VHXhY9mA/R8RYf9 NpSi0bk5FprrTNJoJx9+q/LBGlFrwFZqJpYfL93FMUlkOP47z2U1Z6ihf+HC4vb9 zIS/NRBMgYWcKezbcc7E40XHYChE3SedO809AVAyaz7VASAQsfMDVrih0eu7f+w0 R5FY/32Ks/o0B8Udi3numTAovEE72YjIuuvMZQp9CTGBwNMFQUUsiGAdILSBSULl XNgAJXDOEOyVPDMONaHXQPk4xgDH/iZAcNdgqhnV+lcmgnhwSKAV8hz9/wF/u/H8 qs1OVu0vib9AXJ6ZFFEh =GEhg -----END PGP SIGNATURE----- --------------------------------------------------------------------- To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
