MATLAB Answers

Setting password when connecting to mjs

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yaron
yaron on 23 Jun 2014
Commented: Thomas Ibbotson on 26 Jun 2014
Hello everyone, I've a matlab cluster working, but there is one phanmenom I couldn't track down its source.
Symptom : When some user connecting from his local matlab copy to the cluster for the first time He is being asked for name and password(security level set to 2) After he's done. when he is trying to reconnected to the mjs and run some parallel code only....the mjs tells him the password is not correct(even though he just set it a moment ago).
Tried: This happened several times for different users on different computers. I also checked it myself with dummy user and password as simple as "1"(canceling caps lock effect)
Looking for: If someone knows how to tackle this? or where mjs saves the user profile data? or how I(administrator) can reset users password(without knowing them in advance => cant use changepassword because it require login first) it will be really greatful.

  2 Comments

Thomas Ibbotson
Thomas Ibbotson on 23 Jun 2014
What version of MATLAB are you using? Did the user click the 'Remember forever on this computer' box when they entered their password?
Image Analyst
Image Analyst on 24 Jun 2014
Thomas, put this an an official "Answer" below, so that you can get credit for it.

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Answers (2)

yaron
yaron on 24 Jun 2014
Edited: yaron on 24 Jun 2014
Thank you very much Thomas, I've looked on this command several times and missed the option you mentioned.
For some reason i cannot mark your comment as the answer..mybe repost it so i can mark and close this thread
Have a good week.

  1 Comment

Thomas Ibbotson
Thomas Ibbotson on 25 Jun 2014
Ok, perhaps I have misunderstood your question, I thought that you had found a situation where the user was entering the correct password but it was being rejected. This should not be happening, the ability to reset the password just provides a workaround to the problem, not a solution. In any case, I've moved my comment to an answer.

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Thomas Ibbotson
Thomas Ibbotson on 25 Jun 2014
If you need to you can reset the user's password as the 'admin' user by using 'changePassword' with the username to change as the second argument:
>> help 'parallel.cluster.MJS/changePassword'
changePassword Prompt to change password
changePassword(myCluster) prompts you to change your
password. Your current password must be entered as well as
the new password.
changePassword(myCluster, userName) prompts the cluster
admin user to change the password for the specified user.
The admin user's password must be entered as well as the
user's new password. The enables the admin user to reset a
password if a user has forgotten it.
See also parallel.cluster.MJS/logout,
parallel.cluster.MJS/Username.

  2 Comments

yaron
yaron on 25 Jun 2014
My original question was indeed how to change a password for a user that cannot login.
But as it turned out, you already understood what my next question will be... I login as admin changed the user password and the user still cannot login from his computer. even though , i can enter(b=parcluster()) with his user and the password works for me.
Is there a cache on the local matlab on the user computer we can reset somehow?
Thomas Ibbotson
Thomas Ibbotson on 26 Jun 2014
There is a directory in the user's 'prefdir' called jobmanager_credentials where the hashes of the passwords are cached. You can delete the contents of this directory to remove the cached passwords. You can navigate there in MATLAB with the following code:
cd([prefdir '/../jobmanager_credentials'])
I'd like to create an official bug report for this, can you let me know if this solves your problem? Also what version of MATLAB you are using, and what OS?

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