Backgroundrb devel - Apr 2008 - First call to worker method doesn''t work

I have a worker as follows:

class SampleWorker < BackgrounDRb::MetaWorker
  set_worker_name :sample_worker
  def create(args = nil)
    # this method is called, when worker is loaded for the first time
  end

  def my_method
    # Deliver test e-mail message
    Notifications.deliver_message(1, "DM")
  end
end

I have a rails controller that calls the following code:

    worker = MiddleMan.worker(:sample_worker)
    worker.my_method

The problem is that the first time I load up the page for this action,
the worker method "my_method" doesn''t seem to ever get
called. There
is zero output from any of the backgroundrb log files. If I then
reload the page, it works fine (and continues to work fine until
backgroundrb is restarted).

This happens whether I''m in dev. or prod. mode.

On Thu, Apr 3, 2008 at 8:57 PM, Dylan Markow <dmarkow at gmail.com>
wrote:
> I have a worker as follows:
>
>  class SampleWorker < BackgrounDRb::MetaWorker
>   set_worker_name :sample_worker
>   def create(args = nil)
>     # this method is called, when worker is loaded for the first time
>   end
>
>   def my_method
>     # Deliver test e-mail message
>     Notifications.deliver_message(1, "DM")
>   end
>  end
>
>  I have a rails controller that calls the following code:
>
>     worker = MiddleMan.worker(:sample_worker)
>     worker.my_method
>
>  The problem is that the first time I load up the page for this action,
>  the worker method "my_method" doesn''t seem to ever get
called. There
>  is zero output from any of the backgroundrb log files. If I then
>  reload the page, it works fine (and continues to work fine until
>  backgroundrb is restarted).
>
>  This happens whether I''m in dev. or prod. mode.
>
To clarify, if I restart rails AND backgroundrb at the same time,
everything works fine. it''s only if backgroundrb needs to restart on
its own for some reason. It looks like when the backgroundrb process
is restarted, rails doesn''t realize this as it still sees port 11006
open. So my first request to the page results in the rails plugin
attempting to write data to the socket. I''m assuming this screws
something up, as upon the second attempt at loading my page, "rescue
Errno::EPIPE" at line 64 of backgroundrb.rb is called, thus
re-establishing the connection. I''m assuming this problem may be more
closely related to the packet gem? (Not sure if there is a trac repo
for packet).

On Thu, Apr 3, 2008 at 10:12 PM, Dylan Markow <dmarkow at gmail.com>
wrote:
>
> On Thu, Apr 3, 2008 at 8:57 PM, Dylan Markow <dmarkow at gmail.com>
wrote:
>  > I have a worker as follows:
>  >
>  >  class SampleWorker < BackgrounDRb::MetaWorker
>  >   set_worker_name :sample_worker
>  >   def create(args = nil)
>  >     # this method is called, when worker is loaded for the first time
>  >   end
>  >
>  >   def my_method
>  >     # Deliver test e-mail message
>  >     Notifications.deliver_message(1, "DM")
>  >   end
>  >  end
>  >
>  >  I have a rails controller that calls the following code:
>  >
>  >     worker = MiddleMan.worker(:sample_worker)
>  >     worker.my_method
>  >
>  >  The problem is that the first time I load up the page for this
action,
>  >  the worker method "my_method" doesn''t seem to
ever get called. There
>  >  is zero output from any of the backgroundrb log files. If I then
>  >  reload the page, it works fine (and continues to work fine until
>  >  backgroundrb is restarted).
>  >
>  >  This happens whether I''m in dev. or prod. mode.
>  >
>
>  To clarify, if I restart rails AND backgroundrb at the same time,
>  everything works fine. it''s only if backgroundrb needs to restart
on
>  its own for some reason. It looks like when the backgroundrb process
>  is restarted, rails doesn''t realize this as it still sees port
11006
>  open. So my first request to the page results in the rails plugin
>  attempting to write data to the socket. I''m assuming this screws
>  something up, as upon the second attempt at loading my page, "rescue
>  Errno::EPIPE" at line 64 of backgroundrb.rb is called, thus
>  re-establishing the connection. I''m assuming this problem may be
more
>  closely related to the packet gem? (Not sure if there is a trac repo
>  for packet).
>

One last note: If you have 5 mongrels running of your rails app, then
the worker will fail to fire 5 times (once for each mongrel), though
not always in a row (typically my second request works, but then my
3rd or 4th, etc., won''t)

As it stands now, I''m setting up my deployment files to always restart
backgroundrb BEFORE rails to make sure that once each mongrel fires
up, they each have a valid instance of backgroundrb to point to.

On 4/4/08, Dylan Markow <dmarkow at gmail.com>
wrote:
> On Thu, Apr 3, 2008 at 10:12 PM, Dylan Markow <dmarkow at gmail.com>
wrote:
>  >
>  > On Thu, Apr 3, 2008 at 8:57 PM, Dylan Markow <dmarkow at
gmail.com> wrote:
>  >  > I have a worker as follows:
>  >  >
>  >  >  class SampleWorker < BackgrounDRb::MetaWorker
>  >  >   set_worker_name :sample_worker
>  >  >   def create(args = nil)
>  >  >     # this method is called, when worker is loaded for the
first time
>  >  >   end
>  >  >
>  >  >   def my_method
>  >  >     # Deliver test e-mail message
>  >  >     Notifications.deliver_message(1, "DM")
>  >  >   end
>  >  >  end
>  >  >
>  >  >  I have a rails controller that calls the following code:
>  >  >
>  >  >     worker = MiddleMan.worker(:sample_worker)
>  >  >     worker.my_method
>  >  >
>  >  >  The problem is that the first time I load up the page for this
action,
>  >  >  the worker method "my_method" doesn''t seem
to ever get called. There
>  >  >  is zero output from any of the backgroundrb log files. If I
then
>  >  >  reload the page, it works fine (and continues to work fine
until
>  >  >  backgroundrb is restarted).
>  >  >
>  >  >  This happens whether I''m in dev. or prod. mode.
>  >  >
>  >
>  >  To clarify, if I restart rails AND backgroundrb at the same time,
>  >  everything works fine. it''s only if backgroundrb needs to
restart on
>  >  its own for some reason. It looks like when the backgroundrb process
>  >  is restarted, rails doesn''t realize this as it still sees
port 11006
>  >  open. So my first request to the page results in the rails plugin
>  >  attempting to write data to the socket. I''m assuming this
screws
>  >  something up, as upon the second attempt at loading my page,
"rescue
>  >  Errno::EPIPE" at line 64 of backgroundrb.rb is called, thus
>  >  re-establishing the connection. I''m assuming this problem
may be more
>  >  closely related to the packet gem? (Not sure if there is a trac repo
>  >  for packet).
>  >
>
>
>
> One last note: If you have 5 mongrels running of your rails app, then
>  the worker will fail to fire 5 times (once for each mongrel), though
>  not always in a row (typically my second request works, but then my
>  3rd or 4th, etc., won''t)
>
>  As it stands now, I''m setting up my deployment files to always
restart
>  backgroundrb BEFORE rails to make sure that once each mongrel fires
>  up, they each have a valid instance of backgroundrb to point to.
>
I am tracking down this problem and its related to a bug in ruby
itself (See my post on ruby-core mailing list). In the meanwhile, we
can switch back to starting new connection on each request as a
workaround.

On Thu, 2008-04-03 at 22:24 -0700, Dylan Markow wrote:
> On Thu, Apr 3, 2008 at 10:12 PM, Dylan Markow <dmarkow at gmail.com>
wrote:
> >
> > On Thu, Apr 3, 2008 at 8:57 PM, Dylan Markow <dmarkow at
gmail.com> wrote:
> >  > I have a worker as follows:
> >  >
> >  >  class SampleWorker < BackgrounDRb::MetaWorker
> >  >   set_worker_name :sample_worker
> >  >   def create(args = nil)
> >  >     # this method is called, when worker is loaded for the first
time
> >  >   end
> >  >
> >  >   def my_method
> >  >     # Deliver test e-mail message
> >  >     Notifications.deliver_message(1, "DM")
> >  >   end
> >  >  end
> >  >
> >  >  I have a rails controller that calls the following code:
> >  >
> >  >     worker = MiddleMan.worker(:sample_worker)
> >  >     worker.my_method
> >  >
> >  >  The problem is that the first time I load up the page for this
action,
> >  >  the worker method "my_method" doesn''t seem
to ever get called. There
> >  >  is zero output from any of the backgroundrb log files. If I
then
> >  >  reload the page, it works fine (and continues to work fine
until
> >  >  backgroundrb is restarted).
> >  >
> >  >  This happens whether I''m in dev. or prod. mode.
> >  >
> >
> >  To clarify, if I restart rails AND backgroundrb at the same time,
> >  everything works fine. it''s only if backgroundrb needs to
restart on
> >  its own for some reason. It looks like when the backgroundrb process
> >  is restarted, rails doesn''t realize this as it still sees
port 11006
> >  open. So my first request to the page results in the rails plugin
> >  attempting to write data to the socket. I''m assuming this
screws
> >  something up, as upon the second attempt at loading my page,
"rescue
> >  Errno::EPIPE" at line 64 of backgroundrb.rb is called, thus
> >  re-establishing the connection. I''m assuming this problem
may be more
> >  closely related to the packet gem? (Not sure if there is a trac repo
> >  for packet).
> >
> 
> 
> One last note: If you have 5 mongrels running of your rails app, then
> the worker will fail to fire 5 times (once for each mongrel), though
> not always in a row (typically my second request works, but then my
> 3rd or 4th, etc., won''t)
> 
> As it stands now, I''m setting up my deployment files to always
restart
> backgroundrb BEFORE rails to make sure that once each mongrel fires
> up, they each have a valid instance of backgroundrb to point to.
Hi Dylan,

Sorry for late reply, but I think I nailed down issues you mentioned.

But you need to get latest code, which is not yet in git repo:

1. First update your packet. Get packet code from here:

http://code.google.com/p/packet/source/checkout

Install using: rake gem; sudo gem install packet-0.1.6.gem

2. Get backgroundrb code with fixes from: 

http://backgroundrb.gnufied.org/manual/backgroundrb.tar.gz

Now, you are set. Your problems were because of a bug in Ruby itself and
hence I have reverted connection to old style of connecting on each
request. There was a bug in packet itself for frequent
connection/disconnection. See, if above fixes your problem.

I will be publishing both softwares upstream in few days.

I''m facing this same issue.  Tried to follow hemant''s
recommendation

http://rubyforge.org/pipermail/backgroundrb-devel/2008-April/001675.html

But get an error when running the Rake task:

rake aborted!
no such file to load -- spec/rake/spectask
/Users/brian/packet-read-only/rakefile:7
(See full trace by running task with --trace)

I''m not a rake or a gem guy, so have no clue what to do.  The file / 
spec/rake/spectask doesn''t exist.

Thanks.