Re: [Zope-DB] dealing with dropped database connections
> These are very interesting. However, with SQLRelay, I am still bound > to use SQLRelayDA for Zope, and as Charlie postulated that stale > database connections are in part due to Zope's DA framework, > I wonder how using SQLRelay would address the problem; if the > connection to the SQLRelay server is lost, Zope would similarly hang itself up, wouldn't it? With SQLRelay you have SQLRelay client (in this case Zope DA), that connects to SQLRelay listener that is connected to database. When the network connection to the database is broken then listener becomes disconnected, but when you have some queries from the client (Zope DA) then those reach SQLRelay listener and become hung (in wait state) till connection becomes operational again (im not sure but this may cause all zope threads to be busy and Zope won't be responding). There were some questions about this recently on sqlrelay-discussion. - Maciej Wisniowski ___ Zope-DB mailing list Zope-DB@zope.org http://mail.zope.org/mailman/listinfo/zope-db
Re: [Zope-DB] dealing with dropped database connections
I would try having the SQLRelay listener on the Zope server and see what that does. --Seth martin f krafft ([EMAIL PROTECTED]) wrote: > > also sprach Seth Gottlieb <[EMAIL PROTECTED]> [2006.01.18.1523 +0100]: > > You might also consider using SQLRelay. I wrote some blog posts talking > > about connecting to a relational database. There might be some useful > > information there: > > > > http://contenthere.blogspot.com/2005/12/zoracle-part-i-problem.html > > http://contenthere.blogspot.com/2005/12/zoracle-part-ii-solution.html > > http://contenthere.blogspot.com/2005/12/zoracle-part-iii-connecting-zope-to.html > > These are very interesting. However, with SQLRelay, I am still bound > to use SQLRelayDA for Zope, and as Charlie postulated that stale > database connections are in part due to Zope's DA framework, > I wonder how using SQLRelay would address the problem; if the > connection to the SQLRelay server is lost, Zope would similarly hang > itself up, wouldn't it? > > Or do you recommend running SQLRelay on the Zope server? How does > SQLRelay then manage a connection that is stale? > > Thanks, > > -- > martin; (greetings from the heart of the sun.) > echo mailto: !#^."<*>"|tr "<*> mailto:"; [EMAIL PROTECTED] > > invalid/expired pgp (sub)keys? use subkeys.pgp.net as keyserver! > spamtraps: [EMAIL PROTECTED] > > "women who want to be equal to men lack ambition." > -- timothy leary > ___ Zope-DB mailing list Zope-DB@zope.org http://mail.zope.org/mailman/listinfo/zope-db
Re: [Zope-DB] dealing with dropped database connections
also sprach Seth Gottlieb <[EMAIL PROTECTED]> [2006.01.18.1523 +0100]: > You might also consider using SQLRelay. I wrote some blog posts talking > about connecting to a relational database. There might be some useful > information there: > > http://contenthere.blogspot.com/2005/12/zoracle-part-i-problem.html > http://contenthere.blogspot.com/2005/12/zoracle-part-ii-solution.html > http://contenthere.blogspot.com/2005/12/zoracle-part-iii-connecting-zope-to.html These are very interesting. However, with SQLRelay, I am still bound to use SQLRelayDA for Zope, and as Charlie postulated that stale database connections are in part due to Zope's DA framework, I wonder how using SQLRelay would address the problem; if the connection to the SQLRelay server is lost, Zope would similarly hang itself up, wouldn't it? Or do you recommend running SQLRelay on the Zope server? How does SQLRelay then manage a connection that is stale? Thanks, -- martin; (greetings from the heart of the sun.) \ echo mailto: !#^."<*>"|tr "<*> mailto:"; [EMAIL PROTECTED] invalid/expired pgp (sub)keys? use subkeys.pgp.net as keyserver! spamtraps: [EMAIL PROTECTED] "women who want to be equal to men lack ambition." -- timothy leary signature.asc Description: Digital signature (GPG/PGP) ___ Zope-DB mailing list Zope-DB@zope.org http://mail.zope.org/mailman/listinfo/zope-db
Re: [Zope-DB] dealing with dropped database connections
On 2006-01-18 at 15:17:24 [+0100], martin f krafft <[EMAIL PROTECTED]> wrote: > also sprach Charlie Clark <[EMAIL PROTECTED]> [2006.01.18.1451 +0100]: > > This problem is common to all ZopeDA's connected to network data > > sources. You might want to try using our mxODBCZopeDA with the option > > "Connect on demand" which often helps in these situations. > > Interesting pointer, thanks a lot! > > I wonder how this product determines that a stalled connection > cannot fulfill a demand. > > > However, a lot depends on how your data source and driver are > > configured as the "stale" connection is often serialised even > > though it has been lost. > > I am not sure what you mean with that. Most transactions are > serialised by default these days. I don't understand what that has > to do with stalled connections. > > But you did write serialised *connections*. What are those? Running ODBC over a network involves a lot of components. Assuming there is a network problem causing the connection to fail but the network subsequently recovers, it is possible that the DB driver is in the same state as the ZopeDA and does not discard the previous connection. Unless it does this then the ZopeDA will not attempt to make a new connection. ie, There are limits about what you can do in ZopeDA's because of Zope's architecture. Charlie ___ Zope-DB mailing list Zope-DB@zope.org http://mail.zope.org/mailman/listinfo/zope-db
Re: [Zope-DB] dealing with dropped database connections
You might also consider using SQLRelay. I wrote some blog posts talking about connecting to a relational database. There might be some useful information there: http://contenthere.blogspot.com/2005/12/zoracle-part-i-problem.html http://contenthere.blogspot.com/2005/12/zoracle-part-ii-solution.html http://contenthere.blogspot.com/2005/12/zoracle-part-iii-connecting-zope-to.html The last of the series might be the most relevant. --Seth martin f krafft wrote: also sprach Charlie Clark <[EMAIL PROTECTED]> [2006.01.18.1451 +0100]: This problem is common to all ZopeDA's connected to network data sources. You might want to try using our mxODBCZopeDA with the option "Connect on demand" which often helps in these situations. Interesting pointer, thanks a lot! I wonder how this product determines that a stalled connection cannot fulfill a demand. However, a lot depends on how your data source and driver are configured as the "stale" connection is often serialised even though it has been lost. I am not sure what you mean with that. Most transactions are serialised by default these days. I don't understand what that has to do with stalled connections. But you did write serialised *connections*. What are those? ___ Zope-DB mailing list Zope-DB@zope.org http://mail.zope.org/mailman/listinfo/zope-db -- Seth Gottlieb Optaros, Inc. 60 Canal Street Boston, MA 02114 e: [EMAIL PROTECTED] v: 617.227.1855 ext. 107 f: 617.227.1755 m: 617.852.2956 b: http://contenthere.blogspot.com ___ Zope-DB mailing list Zope-DB@zope.org http://mail.zope.org/mailman/listinfo/zope-db
Re: [Zope-DB] dealing with dropped database connections
also sprach Charlie Clark <[EMAIL PROTECTED]> [2006.01.18.1451 +0100]: > This problem is common to all ZopeDA's connected to network data > sources. You might want to try using our mxODBCZopeDA with the option > "Connect on demand" which often helps in these situations. Interesting pointer, thanks a lot! I wonder how this product determines that a stalled connection cannot fulfill a demand. > However, a lot depends on how your data source and driver are > configured as the "stale" connection is often serialised even > though it has been lost. I am not sure what you mean with that. Most transactions are serialised by default these days. I don't understand what that has to do with stalled connections. But you did write serialised *connections*. What are those? -- martin; (greetings from the heart of the sun.) \ echo mailto: !#^."<*>"|tr "<*> mailto:"; [EMAIL PROTECTED] invalid/expired pgp (sub)keys? use subkeys.pgp.net as keyserver! spamtraps: [EMAIL PROTECTED] *** important disclaimer: by sending an email to any address, that will eventually cause it to end up in my inbox without much interaction, you are agreeing that: - i am by definition, "the intended recipient" - all information in the email is mine to do with as i see fit and make such financial profit, political mileage, or good joke as it lends itself to. in particular, i may quote it on usenet. - i may take the contents as representing the views of your company. - this overrides any disclaimer or statement of confidentiality that may be included on your message. signature.asc Description: Digital signature (GPG/PGP) ___ Zope-DB mailing list Zope-DB@zope.org http://mail.zope.org/mailman/listinfo/zope-db
Re: [Zope-DB] dealing with dropped database connections
martin f krafft wrote: Hi, a client of mine complains about dropped database connections (SybaseDA), which wreak havoc. For instance, if the network goes down for a while, the DA is left in an irrecoverable state. Short of a regular wget to the manage interface to restart the DA, what can be done? Is this something about SybaseDA (which is no longer maintained), or a common problem? What would you advise, short of hunting down the problem and fixing it? This problem is common to all ZopeDA's connected to network data sources. You might want to try using our mxODBCZopeDA with the option "Connect on demand" which often helps in these situations. However, a lot depends on how your data source and driver are configured as the "stale" connection is often serialised even though it has been lost. Charlie ___ Zope-DB mailing list Zope-DB@zope.org http://mail.zope.org/mailman/listinfo/zope-db
[Zope-DB] dealing with dropped database connections
Hi, a client of mine complains about dropped database connections (SybaseDA), which wreak havoc. For instance, if the network goes down for a while, the DA is left in an irrecoverable state. Short of a regular wget to the manage interface to restart the DA, what can be done? Is this something about SybaseDA (which is no longer maintained), or a common problem? What would you advise, short of hunting down the problem and fixing it? -- martin; (greetings from the heart of the sun.) \ echo mailto: !#^."<*>"|tr "<*> mailto:"; [EMAIL PROTECTED] invalid/expired pgp (sub)keys? use subkeys.pgp.net as keyserver! spamtraps: [EMAIL PROTECTED] "the surest way to corrupt a youth is to instruct him to hold in higher esteem those who think alike than those who think differently." -- friedrich nietzsche signature.asc Description: Digital signature (GPG/PGP) ___ Zope-DB mailing list Zope-DB@zope.org http://mail.zope.org/mailman/listinfo/zope-db
