DB Hangs

[sureshht]

Hi Everybody,
What are the various reasons for DB hang.? If the user complains of DB session is hanging, What are all the possible things for DB hang?. How do u start resolving it. step by step please.
Thanking you
Suresh.H.T

[SANJAY_G]

What do you mean by db hangs ?? Is it a client is getting no response or background process are freezed or died?
Try to make local connect from server and check the background process status. If everything is OK there then problem lies either client PC or listener or network.

HTH

[hrishy]

Hi Suresh

1)Check the alert log to see wheather something strange there

2)Ask wheather only one user or all users are compalainig

3)Check what programme he uses to make connections to the database

4)Check listener log files

5)Trace that users session and look for what sql he is executing


6)check the network..

recently i had a problem..wherein the company had lied to me saying that they a 2Gb wan link..some users use to compalin that the database used to be slow..after three days of investigation here are the results there is an EJB sitting behind a WAN link which makes call to the database..which causes the slow response.

a simple test of ping 176.*.*.* -t l 2048 revealed this :-)

i guess others can chip in their experinces..

[pando]

he is blocked

he is running a big query

[hrishy]

Hi Suresh

1)Check the alert log to see wheather something strange there

2)Ask wheather only one user or all users are compalainig

3)Check what programme he uses to make connections to the database

4)Check listener log files

5)Trace that users session and look for what sql he is executing


6)check the network..

7)check the servers /var/adm/messges files event viewer in case your on NT

8)learn about os tools like vmstat ,iostat,winNT performnace monitor

9)If you use a App server /Web server learn basic troubleshooting of them..

recently i had a problem..wherein the company had lied to me saying that they a 2Gb wan link..some users use to compalin that the database used to be slow..after three days of investigation here are the results there is an EJB sitting behind a WAN link which makes call to the database..which causes the slow response.

I have solved my real life problems with the above steps..Not necassarily in the order..

a simple test of ping 176.*.*.* -t l 2048 revealed this :-)

i guess others can chip in their experiences..


regards
Hrishy

[akhadar]

Lot of times DB will not hang but the other people and other environments will make it appear as hanging by force.As for as me concerned it is mainly due to network,negligence on the part of end user not following the rules.