reconnect

Hello,

I have a perl script which runs in daemon mode. It works fine. Now
I would like to implement failover handling.
Do I need to reconnect if my database goes away and goes back?
1. db shutdown
2. some sql queries which fail (error handling)
3. db back
4. ?reconnect?
4?5. sql queries
....

Thanks in advance,
Thomas


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Re: reconnect

why don't you give it a try and restart mysqld and after
mysqld is up again check if the open handle is connected=20
still/again.
you might want to check the DBI->ping method to
recognize a broken link so that you don't "loose"
any queries. depending on your needs you might pause
until mysqld is back or immediately try to reconnect
or use replication functionality or die in panic :-)

Uli

At 10:24 20.08.02 +0200, Thomas Jalsovsky wrote:
>
>Hello,
>
> I have a perl script which runs in daemon mode. It works fine. Now=20
>I would like to implement failover handling.=20
> Do I need to reconnect if my database goes away and goes back?
>1. db shutdown
>2. some sql queries which fail (error handling)
>3. db back
>4. ?reconnect?=20
>4?5. sql queries
>...
>
> Thanks in advance,
> Thomas
>

--=20
-----------------------------------------------
Ulrich Borchers
Brandenberger Straße 18, 41065 Mönchengladbach
fon +49-2161-175883
icq 1282868
-----------------------------------------------


------------------------------------------------------------ ---------
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posting. To request this thread, e-mail msql-mysql-modules-thread1891@lists.mysql.com

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Re: reconnect

why don't you give it a try and restart mysqld and after
mysqld is up again check if the open handle is connected=20
still/again.
you might want to check the DBI->ping method to
recognize a broken link so that you don't "loose"
any queries. depending on your needs you might pause
until mysqld is back or immediately try to reconnect
or use replication functionality or die in panic :-)

Uli

At 10:24 20.08.02 +0200, Thomas Jalsovsky wrote:
>
>Hello,
>
> I have a perl script which runs in daemon mode. It works fine. Now=20
>I would like to implement failover handling.=20
> Do I need to reconnect if my database goes away and goes back?
>1. db shutdown
>2. some sql queries which fail (error handling)
>3. db back
>4. ?reconnect?=20
>4?5. sql queries
>...
>
> Thanks in advance,
> Thomas
>

--=20
-----------------------------------------------
Ulrich Borchers
Brandenberger Straße 18, 41065 Mönchengladbach
fon +49-2161-175883
icq 1282868
-----------------------------------------------


------------------------------------------------------------ ---------
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posting. To request this thread, e-mail msql-mysql-modules-thread1891@lists.mysql.com

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Re: reconnect

Zitiere Thomas Jalsovsky :

>
> Do I need to reconnect if my database goes away and goes back?
> 1. db shutdown
> 2. some sql queries which fail (error handling)
> 3. db back
> 4. ?reconnect?
> 4?5. sql queries

The driver has a certain degree of ability to
reconnect. However, that only works in the absence
of transactions, which you are most probably going
to use.

I would suggest to encapsulate the database handling.
If something goes wrong, assume the database connection
to be dead. Close it and reconnect.



------------------------------------------------------------ ---------
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posting. To request this thread, e-mail msql-mysql-modules-thread1892@lists.mysql.com

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Re: reconnect

Zitiere Thomas Jalsovsky :

>
> Do I need to reconnect if my database goes away and goes back?
> 1. db shutdown
> 2. some sql queries which fail (error handling)
> 3. db back
> 4. ?reconnect?
> 4?5. sql queries

The driver has a certain degree of ability to
reconnect. However, that only works in the absence
of transactions, which you are most probably going
to use.

I would suggest to encapsulate the database handling.
If something goes wrong, assume the database connection
to be dead. Close it and reconnect.



------------------------------------------------------------ ---------
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