On 5/19/2015 7:53 AM, javalishixml wrote:
I doubt you're going to be able to do this in httpd, unless you have a very
simple, straight forward way of identifying the robots.
Yes. I just want to have a way to block the duplicated requests at httpd level.
After all, my website has to face the the big concurrency issue.
I understand that's what you want. What we're telling you is that you
probably won't be able to do that.
Let me ask the question again, that Chris asked before: how do you tell
that a given request is from a robot?
The answer to that question will determine if you can block it with httpd.
At 2015-05-19 19:35:26, "David kerber" <dcker...@verizon.net> wrote:
On 5/19/2015 1:03 AM, javalishixml wrote:
Thanks a lot for your information.
This solution is based on tomcat level. If I always handle this issue at java
level, I'm afraid it has performance issue. Because this web site afford a very
big concurrency access.
Taking a consideration on its basic architect tomcat+apache, I think the best
way to move this solution from tomcat to apache. So do you have some good
solution at apache's configuration? I understand this is a mail list for
tomcat.. but just want to get any information
I doubt you're going to be able to do this in httpd, unless you have a
very simple, straight forward way of identifying the robots.
Thanks,
At 2015-05-19 04:00:28, "Christopher Schultz" <ch...@christopherschultz.net>
wrote:
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA256
To whom it may concern,
On 5/18/15 11:44 AM, javalishixml wrote:
I have a website. It is built by apache + tomcat.
Now we make a lottery activity at this website. But we find that
some robots always raise the duplicated requests to hit this
lottery activity. It causes that robots almost get all the awards.
So we just want to block these kind of duplicated requests at every
interval unit. For example, we set the interval unit is 3 seconds.
The if the robot want to hit the lottery activity in 3 seconds, the
website could block this action.
So how to do it? I suppose if we do it at tomcat level, is it a
very low performance? Can I do it at apache level? how to do it? If
I could not do it apache level, can I do it by setting sth at
tomcat?
If you have a way to identify a "duplicate" request (e.g. using a
fingerprint of the request that you can check during that 3-second
interval), then this is conceptually very easy.
It may not be great for performance, but you'll have to weigh that
against your own requirements. (For example, which is worse: poor
performance, or a site where only robots ever win the lottery?)
This will not be something you can configure in Apache httpd or
Tomcat. This will have to be an application thing (unless you can
describe the fingerprint technique to some httpd module such as
mod_security or mod_qos and then allow it to discard duplicates).
Back to the solution:
1. Take a fingerprint of the request
2. Lookup the fingerprint in a database of previous requests
( fingerprint -> latest timestamp )
3. If the fingerprint appears in your database and the timestamp is
less than 3 seconds ago, discard the request
4. Otherwise, store the current timestamp and fingerprint in the databas
e
For a database, I might recommend something like memcached or another
in-memory-style database. An in-memory key-value store is really what
you are looking for. Memcached has a nice feature where values can
automatically time-out (e.g. they are invalid after 3 seconds), so you
can make your application code a bit simpler because you'll never have
a value in the database that is not valid.
Hope that helps,
- -chris
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2
Comment: GPGTools - http://gpgtools.org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=Q/ki
-----END PGP SIGNATURE-----
---------------------------------------------------------------------
To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org
For additional commands, e-mail: users-h...@tomcat.apache.org
---------------------------------------------------------------------
To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org
For additional commands, e-mail: users-h...@tomcat.apache.org
---------------------------------------------------------------------
To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org
For additional commands, e-mail: users-h...@tomcat.apache.org
