Information being Erased

[cdlfreedom]

I have not done much customizing of the program, only labeling and ordering fields.

for some reason, every once in awhile - when my user updates a record most of the information gets erased. I have it set into groups, and the first group, that has the contact info is saved. the following groups are wiped of information they had already had saved, which i have confirmed saved properly and was able to be open again - previously.

any reason that this would happen? any point in a direction would be great as i'm a little lost. I can only think of maybe the session expired, but that shouldn'y wipe it that should just prevent saving.

thanks in advance,
Kyle
CDLFreedom

[cdlfreedom]

no one has any idea? it seems this has happened again, this time the information re-appeared after a short while. the thing that confuses me most though - is that i checked the database itself and saw no information, however within an hour it was back. how is this possible?

i have confirmed it is NOT user(s), removing or replacing information, or more than 1 user on a record at a time.

[shannah]

This is very strange.

Have you confirmed that the information is actually erased from the database (as opposed to just through the web interface of Xataface?). One possibility is that if two people are updating the same record at the same time, they could be overwriting each other's work.

Xataface doesn't currently have an automatic locking mechanism to prevent two people from editing the same record at the same time.

[cdlfreedom]

yes in the first instance i checked the database and saw it empty - however that time the user re-entered the information so i DO NOT know for sure that it is the same issue as the second instance, where information was temporarily absent.
in the case of 2 people working at once, it wouldn't erase anything though would it - unless a user did that. i assume it would simply reset it to whatever the last user that hit save had on their screen, is this right?

[shannah]

The race condition when two users are updating the same record at the same time works as follows:

User 1 Opens the edit form for record X
User 2 Opens the edit form for record X
User 1 Adds a whole bunch of information and saves record X.
User 2 Adds a tiny bit of information and saves it

Result: All of User 1's changes are gone. The record content consists of User 2's version completely.

The worst case scenario is where you have really long session timeouts that would allow the user to keep a browser window open for days. A user could potentially open a form, leave it for a day or two, and hit save. This would wipe out any information that an users had added in the previous day or two.

[cdlfreedom]

yeah and i can account for an error like that by just telling them , but is there anything that may cause that not specifically related to xataface necessarily? something with mysql? thank you for your help, i'm really just trying to narrow it down, i think user error may be a part of it but i can't just say that, so i have to cover my bases on the possible reasons that could happen.

thanks again!

[shannah]

Strange things are always possible. It's hard to say without a full inspection. Sometimes the back-up scripts cause things to be overwritten that shouldn't be.

But it's all speculation. You probably need to really look through your logs. Turn on MySQL query logging so you can follow exactly what query causes things to be deleted and when.

[cdlfreedom]

I updated to the newest version via SVN and thought it had fixed it, as we've been fine for awhile. but today it happened again, luckily though i was able to get more information.

it's not as i thought before. no information is actually being erased (so wrong title to start). it's only the currently entered information not being saved. so if the record held name, address, and phone - and you type in the email and click save - it says record succesfully saved but the email field is empty and was not actually saved..

obviously this is quite different than i thought, it doesn't ask them to login again or anything, so i assume the session is good. are the logs still my best bet? any other ideas with the new information?

[shannah]

Any info or logs would be helpful.
Info:
Versions of Xataface, MySQL, Apache, OS, PHP
Any logs you have surrounding the non-working save.

If you can put together a repeatable test that will produce these results it would also be good. Such a test might involve a table schema, appropriate INI files, and possibly delegate class definitions if they are required to reproduce the problem.

-Steve