Re: One user seeing another user's data
Hello Anotonio,
Thanks for your reply.
We are using JSPs and invoke java beans from them. We have the scope parameter set to
'application' in JSPs. I will look into the bean source code and check for non-final
static variables.
Regards,
Anbu
Antonio_Fiol_Bonnín [EMAIL PROTECTED] wrote:
Hi,
- Try to turn all your servlet's non-final STATIC or INSTANCE variables
into LOCAL scope variables. This is definitely the first step, and will
likely remove 90% of problems.
For singletons or static variables outside your servlet:
- Concentrate all your accesses to each of them in a short portion of
code (put all accesses together). Surround them with a
synchronized(object) { }. You will remove 80% of the remaining problems.
- If a collection is not in local scope, use a synchronized version of
it. (??%)
For the rest, you will have to figure out The most important point
once the above are OK, in my opinion, is that you know the business
logic concerning object access and its required independence. It's more
difficult, but you probably know that better than anyone.
Yours,
Antonio Fiol
Anbu wrote:
Hello All,
I think that this problem (one user seeing another user's data) might be due to
threadedness/concurrency of Tomcat. Ofcourse there could be problem with the JSP
application too.
Can anyone throw some light on the possible session mixups happening with Tomcat
server? I have seen the dev mailing list that such a thing happens when there are two
or more tomcat server instances.
Thanks and Regards,
Anbu
Keywords (for easier searches): threading issues, session mixup,
concurrency problems.
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RE: One user seeing another user's data
well uh perhaps I'm misunderstanding something, but 'application'
is the completely wrong scope, if you want the javabeans to *not* be
shared between all users of your application.
-Original Message-
From: Anbu [mailto:[EMAIL PROTECTED]
Sent: Tuesday, February 24, 2004 5:39 AM
To: Tomcat Users List
Subject: Re: One user seeing another user's data
Hello Anotonio,
Thanks for your reply.
We are using JSPs and invoke java beans from them. We have
the scope parameter set to 'application' in JSPs. I will look
into the bean source code and check for non-final static variables.
Regards,
Anbu
Antonio_Fiol_Bonnín [EMAIL PROTECTED] wrote:
Hi,
- Try to turn all your servlet's non-final STATIC or INSTANCE
variables
into LOCAL scope variables. This is definitely the first
step, and will
likely remove 90% of problems.
For singletons or static variables outside your servlet:
- Concentrate all your accesses to each of them in a short portion of
code (put all accesses together). Surround them with a
synchronized(object) { }. You will remove 80% of the
remaining problems.
- If a collection is not in local scope, use a synchronized
version of
it. (??%)
For the rest, you will have to figure out The most important point
once the above are OK, in my opinion, is that you know the business
logic concerning object access and its required independence.
It's more
difficult, but you probably know that better than anyone.
Yours,
Antonio Fiol
Anbu wrote:
Hello All,
I think that this problem (one user seeing another user's
data) might
be due to threadedness/concurrency of Tomcat. Ofcourse there
could be problem with the JSP application too.
Can anyone throw some light on the possible session mixups happening
with Tomcat server? I have seen the dev mailing list that
such a thing happens when there are two or more tomcat server
instances.
Thanks and Regards,
Anbu
Keywords (for easier searches): threading issues, session mixup,
concurrency problems.
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RE: One user seeing another user's data
Hello All, I think that this problem (one user seeing another user's data) might be due to threadedness/concurrency of Tomcat. Ofcourse there could be problem with the JSP application too. Can anyone throw some light on the possible session mixups happening with Tomcat server? I have seen the dev mailing list that such a thing happens when there are two or more tomcat server instances. Thanks and Regards, Anbu Kal Govindu [EMAIL PROTECTED] wrote: We had this problem on our first JSP application. One of the things we had to fix it was to remove all variable definitions from and move them to . Kal -Original Message- From: Antonio Fiol Bonnin [mailto:[EMAIL PROTECTED] Sent: Tuesday, February 17, 2004 2:17 AM To: Tomcat Users List Subject: Re: One user seeing another user's data Hi Kuloth, Seatch Tomcat-user for concurrency problems or threading issues. There has been recent discussion on the topic. Concurrency problems are the main source of session mix-up. Also look for instance variables (hint: avoid them in Servlets) Antonio Fiol Anbu wrote: Hello Bill and All, Could any one of you throw some light on a problem that I am facing on Apache 1.3.28/Mod-jk 1.2.0/Tomcat 4.0.6 setup? The problem is that an user could see someother user's data (some kind of session mix up). When I searched the tomcat-dev list I found that Bill had replied that the problem could be related to error handling and it is not a synchorinazation problem. Bill, as you have already seen and analyized this issue, could you please help me on this issue ? Thank you all in advance. Regards, Kuloth CONFIDENTIALITY NOTE: All e-mail sent to or from this address will be received by the Waterfield Group corporate e-mail system and is subject to archival, monitoring, and/or review by someone other than the recipient or the sender. This e-mail and any of its attachments may contain proprietary information, which is privileged and confidential. This e-mail is intended solely for the use of the individual or entity to which it is addressed. If you are not the intended recipient of this e-mail, you are hereby notified that any dissemination, distribution, copying, or action taken in relation to the contents of and attachments to this e-mail is strictly prohibited and may be unlawful. If you have received this e-mail in error, please notify the sender immediately and permanently delete the original and any copy of this e-mail and any printout. Thank you. - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] - Do you Yahoo!? Yahoo! Mail SpamGuard - Read only the mail you want.
Re: One user seeing another user's data
Hi,
- Try to turn all your servlet's non-final STATIC or INSTANCE variables
into LOCAL scope variables. This is definitely the first step, and will
likely remove 90% of problems.
For singletons or static variables outside your servlet:
- Concentrate all your accesses to each of them in a short portion of
code (put all accesses together). Surround them with a
synchronized(object) { }. You will remove 80% of the remaining problems.
- If a collection is not in local scope, use a synchronized version of
it. (??%)
For the rest, you will have to figure out The most important point
once the above are OK, in my opinion, is that you know the business
logic concerning object access and its required independence. It's more
difficult, but you probably know that better than anyone.
Yours,
Antonio Fiol
Anbu wrote:
Hello All,
I think that this problem (one user seeing another user's data) might be due to threadedness/concurrency of Tomcat. Ofcourse there could be problem with the JSP application too.
Can anyone throw some light on the possible session mixups happening with Tomcat server? I have seen the dev mailing list that such a thing happens when there are two or more tomcat server instances.
Thanks and Regards,
Anbu
Keywords (for easier searches): threading issues, session mixup,
concurrency problems.
smime.p7s
Description: S/MIME Cryptographic Signature
RE: One user seeing another user's data
Hello Antonio, Kal and All, Thanks for your suggestions and hints. Regards, Kuloth --- Kal Govindu [EMAIL PROTECTED] wrote: We had this problem on our first JSP application. One of the things we had to fix it was to remove all variable definitions from %!...% and move them to %...%. Kal -Original Message- From: Antonio Fiol Bonnin [mailto:[EMAIL PROTECTED] Sent: Tuesday, February 17, 2004 2:17 AM To: Tomcat Users List Subject: Re: One user seeing another user's data Hi Kuloth, Seatch Tomcat-user for concurrency problems or threading issues. There has been recent discussion on the topic. Concurrency problems are the main source of session mix-up. Also look for instance variables (hint: avoid them in Servlets) Antonio Fiol Anbu wrote: Hello Bill and All, Could any one of you throw some light on a problem that I am facing on Apache 1.3.28/Mod-jk 1.2.0/Tomcat 4.0.6 setup? The problem is that an user could see someother user's data (some kind of session mix up). When I searched the tomcat-dev list I found that Bill had replied that the problem could be related to error handling and it is not a synchorinazation problem. Bill, as you have already seen and analyized this issue, could you please help me on this issue ? Thank you all in advance. Regards, Kuloth CONFIDENTIALITY NOTE: All e-mail sent to or from this address will be received by the Waterfield Group corporate e-mail system and is subject to archival, monitoring, and/or review by someone other than the recipient or the sender. This e-mail and any of its attachments may contain proprietary information, which is privileged and confidential. This e-mail is intended solely for the use of the individual or entity to which it is addressed. If you are not the intended recipient of this e-mail, you are hereby notified that any dissemination, distribution, copying, or action taken in relation to the contents of and attachments to this e-mail is strictly prohibited and may be unlawful. If you have received this e-mail in error, please notify the sender immediately and permanently delete the original and any copy of this e-mail and any printout. Thank you. - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] __ Do you Yahoo!? Yahoo! Mail SpamGuard - Read only the mail you want. http://antispam.yahoo.com/tools - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
RE: One user seeing another user's data
We had this problem on our first JSP application. One of the things we had to fix it was to remove all variable definitions from %!...% and move them to %...%. Kal -Original Message- From: Antonio Fiol Bonnin [mailto:[EMAIL PROTECTED] Sent: Tuesday, February 17, 2004 2:17 AM To: Tomcat Users List Subject: Re: One user seeing another user's data Hi Kuloth, Seatch Tomcat-user for concurrency problems or threading issues. There has been recent discussion on the topic. Concurrency problems are the main source of session mix-up. Also look for instance variables (hint: avoid them in Servlets) Antonio Fiol Anbu wrote: Hello Bill and All, Could any one of you throw some light on a problem that I am facing on Apache 1.3.28/Mod-jk 1.2.0/Tomcat 4.0.6 setup? The problem is that an user could see someother user's data (some kind of session mix up). When I searched the tomcat-dev list I found that Bill had replied that the problem could be related to error handling and it is not a synchorinazation problem. Bill, as you have already seen and analyized this issue, could you please help me on this issue ? Thank you all in advance. Regards, Kuloth CONFIDENTIALITY NOTE: All e-mail sent to or from this address will be received by the Waterfield Group corporate e-mail system and is subject to archival, monitoring, and/or review by someone other than the recipient or the sender. This e-mail and any of its attachments may contain proprietary information, which is privileged and confidential. This e-mail is intended solely for the use of the individual or entity to which it is addressed. If you are not the intended recipient of this e-mail, you are hereby notified that any dissemination, distribution, copying, or action taken in relation to the contents of and attachments to this e-mail is strictly prohibited and may be unlawful. If you have received this e-mail in error, please notify the sender immediately and permanently delete the original and any copy of this e-mail and any printout. Thank you. - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: One user seeing another user's data
Hi Kuloth, Seatch Tomcat-user for concurrency problems or threading issues. There has been recent discussion on the topic. Concurrency problems are the main source of session mix-up. Also look for instance variables (hint: avoid them in Servlets) Antonio Fiol Anbu wrote: Hello Bill and All, Could any one of you throw some light on a problem that I am facing on Apache 1.3.28/Mod-jk 1.2.0/Tomcat 4.0.6 setup? The problem is that an user could see someother user's data (some kind of session mix up). When I searched the tomcat-dev list I found that Bill had replied that the problem could be related to error handling and it is not a synchorinazation problem. Bill, as you have already seen and analyized this issue, could you please help me on this issue ? Thank you all in advance. Regards, Kuloth smime.p7s Description: S/MIME Cryptographic Signature
