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PHP broken pipe in fork

php.internals

Unnamed Person

21 years ago
Hi, i'm using firebird 1.5.1 on a linux machine with a php script I'm using a query in loop and go through all records to do some operations in the middle of the script i fork(); to do other things When i return to the parent process i try to make one update and i get the following error [nativecode=Unable to complete network request to host "127.0.0.1". Error writing data to the connection. Broken pipe] And continue the loop of the records of the query. It apears that the fork and the wait from pcntl closes the sockets to the database. Is this a regular beaviour ? How can it be solved ? I'm using Pear DB for database access. Thank you in advance Rui Francisco

Shaun Thomas

21 years ago
user@domain.invalid wrote:
> I'm using a query in loop and go through all records to do some > operations in the middle of the script i fork(); to do other things > When i return to the parent process i try to make one update and i > get the following error [nativecode=Unable to complete network > request to host "127.0.0.1". Error writing data to the connection. > Broken pipe]
That would be a fairly well known issue with PHP. You're running into the same thing we encountered about 2 years ago. What happens is that your child process is closing the mysql connection as part of its standard PHP cleanup procedures, leaving the parent with a broken connection. I'd recommend provisioning a method so that your child makes its own new connection, and does not use the parent's connection at all. Since all php scripts clean up before exiting, you need to make sure all resources in use by the child are not needed by the parent after the child exits.
-- Shaun M. Thomas INN Database Administrator Phone: (309) 743-0812 Fax : (309) 743-0830 Email: sthomas@townnews.com Web : www.townnews.com

Sara Golemon

21 years ago
>> I'm using a query in loop and go through all records to do some >> operations in the middle of the script i fork(); to do other things >> When i return to the parent process i try to make one update and i >> get the following error [nativecode=Unable to complete network >> request to host "127.0.0.1". Error writing data to the connection. >> Broken pipe] > > That would be a fairly well known issue with PHP. You're running into > the same thing we encountered about 2 years ago. What happens is that > your child process is closing the mysql connection as part of its > standard PHP cleanup procedures, leaving the parent with a broken > connection. > > I'd recommend provisioning a method so that your child makes its own new > connection, and does not use the parent's connection at all. Since all > php scripts clean up before exiting, you need to make sure all resources > in use by the child are not needed by the parent after the child exits. >
Or just use persistent resources (i.e.: mysql_pconnect() ) -Sara

Unnamed Person

21 years ago
The child process doesn't use any database connection, just to run some shell scripts, but it closes the connection anyway. I initialy used PEAR DB and then _pconnect functions but the result is the same. Was the bug solved two years ago ? How was it solved ? Thank you Rui Francisco Shaun Thomas wrote:

Shaun Thomas

21 years ago
user@domain.invalid wrote:
> The child process doesn't use any database connection, just to run some > shell scripts, but it closes the connection anyway.
You still don't get it. As a fork, the child process has all of the same resources as the parent before the fork occurred. When the child exits, it will close those resources, leaving the parent high and dry.
> I initialy used PEAR DB and then _pconnect functions but the result is > the same.
Not sure why that would be. Maybe the CLI doesn't honor _pconnect based functions, since pconnect was originally designed for keeping connections persistent across server processes.
> Was the bug solved two years ago ?
This is *not* a bug. It is a natural part of how PHP cleans up after itself. There are many ways to circumvent this, but are left as an exercise for the programmer. In our case, we did a test on the connection at all times before using it, and reconnected if the resource was ever closed or invalid; your mileage may vary.
-- Shaun M. Thomas INN Database Administrator Phone: (309) 743-0812 Fax : (309) 743-0830 Email: sthomas@townnews.com Web : www.townnews.com