Re: [Zope-dev] Connection policies.

2003-10-01 Thread Shane Hathaway
Chris McDonough wrote:
Forgive me, but I don't see the motivation: a database connection 
represents a large chunk of RAM.  Won't the new policies just cause 
overloaded sites to also run out of RAM?


No.  Well, at least one implementation won't. ;-)  We don't reserve a pool of
database connections for the special servers.  The connection policy can use a
temporary connection, which AFAIK does not keep a ZODB cache.
But you're right in the sense that this won't help RAM-bound applications;
that's what AutoLance is for.  It will help debug sites where there's a
database connection leak or sites where all public threads are tied up
waiting for a database connection (if only to be able to restart it via
the mgmt interface).
Ah!  Ok, so it's meant for admin-only access.  That's a fine idea.

Shane

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Re: [Zope-dev] Connection policies.

2003-10-01 Thread Chris McDonough
> Forgive me, but I don't see the motivation: a database connection 
> represents a large chunk of RAM.  Won't the new policies just cause 
> overloaded sites to also run out of RAM?

No.  Well, at least one implementation won't. ;-)  We don't reserve a pool of
database connections for the special servers.  The connection policy can use a
temporary connection, which AFAIK does not keep a ZODB cache.

But you're right in the sense that this won't help RAM-bound applications;
that's what AutoLance is for.  It will help debug sites where there's a
database connection leak or sites where all public threads are tied up
waiting for a database connection (if only to be able to restart it via
the mgmt interface).

- C



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Re: [Zope-dev] Connection policies.

2003-10-01 Thread Shane Hathaway
Chris McDonough wrote:
Yesterday I made a Zope 2 branch named
chrism-zserver-connection-policies-branch.
The benefits that result from the changes are that you can "reserve" a
thread pool for a particular set of ZServer servers, and that you can
specify alternate ZODB "connection policies" on a per-server basis.  

This will allow sites which are having resource exhaustion problems
(e.g. running out of threads, running out of database connections) to
continue to be accessible via servers running on "special" ports for
debugging and maintenance purposes.
I'd like to merge this into the trunk at some point, but I'd like some
feedback first.
Forgive me, but I don't see the motivation: a database connection 
represents a large chunk of RAM.  Won't the new policies just cause 
overloaded sites to also run out of RAM?

Shane

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[Zope-dev] Connection policies.

2003-10-01 Thread Chris McDonough
Yesterday I made a Zope 2 branch named
chrism-zserver-connection-policies-branch.

The benefits that result from the changes are that you can "reserve" a
thread pool for a particular set of ZServer servers, and that you can
specify alternate ZODB "connection policies" on a per-server basis.  

This will allow sites which are having resource exhaustion problems
(e.g. running out of threads, running out of database connections) to
continue to be accessible via servers running on "special" ports for
debugging and maintenance purposes.

I'd like to merge this into the trunk at some point, but I'd like some
feedback first.

-- 
Chris McDonough <[EMAIL PROTECTED]>
Zope Corporation


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