# Rinda: random ECONNREFUSED error

**URL:** <https://www.ruby-forum.com/t/rinda-random-econnrefused-error/148080>\
**Category:** Ruby\
**Created:** [September 9, 2008, 1:00am UTC](https://www.ruby-forum.com/t/rinda-random-econnrefused-error/148080 "2008-09-09T01:00:24Z")\
**Posts on this page:** 4\
**Page:** 1

<div class="post-metadata">

**Author:** ![andreas](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/ee7513/32.png) [@andreas](https://www.ruby-forum.com/u/andreas)\
**Post date:** [September 9, 2008, 1:00am UTC](https://www.ruby-forum.com/t/rinda-random-econnrefused-error/148080/1 "2008-09-09T01:00:24Z")

</div>

I was following rinda examples from  
[http://segment7.net/projects/ruby/drb/rinda/ringserver.html](http://segment7.net/projects/ruby/drb/rinda/ringserver.html) and randomly  
got  
ECONNREFUSED: Connection refused - connect(2)  
error from running the list\_services code.

I tried a variation from ringserver example as attached below. I ran it  
on different machines (all Linux RedHat 2.4) with ruby 1.8.6p111+ and  
1.8.7p22. Same behavior. Eventually, I’ll get several  
#\<Errno::ECONNREFUSED: Connection refused - connect(2)\> errors.

There is great chance that the mistake is in my code or due to the lack  
of my understanding, so I would appreciate if someone could point it  
out. Thanks in advance

-andre

> foreach i (\*) # I have ± 100 files  
> foreach? ruby client.rb  
> foreach? end

– server.rb –  
require ‘rinda/tuplespace’  
require ‘rinda/ring’  
include Rinda  
DRb.start\_service  
RingServer.new TupleSpace.new  
DRb.thread.join

– service.rb –  
require ‘rinda/ring’  
include Rinda  
DRb.start\_service  
RingFinger.primary.write [:service, “Test1”]  
DRb.thread.join

– client.rb –  
require ‘rinda/ring’  
include Rinda  
DRb.start\_service  
puts RingFinger.primary.read([:service, nil])[1]

---

<div class="post-metadata">

**Author:** ![andreas](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/ee7513/32.png) [@andreas](https://www.ruby-forum.com/u/andreas)\
**Post date:** [September 9, 2008, 2:49am UTC](https://www.ruby-forum.com/t/rinda-random-econnrefused-error/148080/2 "2008-09-09T02:49:00Z")

</div>

Andreas Sun wrote:

> I was following rinda examples from  
> [http://segment7.net/projects/ruby/drb/rinda/ringserver.html](http://segment7.net/projects/ruby/drb/rinda/ringserver.html) and randomly  
> got  
> ECONNREFUSED: Connection refused - connect(2)  
> error from running the list\_services code.

> – server.rb –  
> require ‘rinda/tuplespace’  
> require ‘rinda/ring’  
> include Rinda  
> DRb.start\_service  
> RingServer.new TupleSpace.new  
> DRb.thread.join
> 
> – service.rb –  
> require ‘rinda/ring’  
> include Rinda  
> DRb.start\_service  
> RingFinger.primary.write [:service, “Test1”]  
> DRb.thread.join
> 
> – client.rb –  
> require ‘rinda/ring’  
> include Rinda  
> DRb.start\_service  
> puts RingFinger.primary.read([:service, nil])[1]

Good question. I can never get primary() to work either.

I always end up using:

finger=Rinda::RingFinger.new([BROADCAST\_ADDRESS])

remote\_tuplespace=finger.lookup\_ring\_any

for the client and service code…

djief

---

<div class="post-metadata">

**Author:** ![andreas](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/ee7513/32.png) [@andreas](https://www.ruby-forum.com/u/andreas)\
**Post date:** [September 9, 2008, 4:01pm UTC](https://www.ruby-forum.com/t/rinda-random-econnrefused-error/148080/3 "2008-09-09T16:01:50Z")

</div>

> I always end up using:
> 
> finger=Rinda::RingFinger.new([BROADCAST\_ADDRESS])
> 
> remote\_tuplespace=finger.lookup\_ring\_any
> 
> for the client and service code…

This seems works. Thank you.

You’ve got me looked at the RingFinger class. The default broadcast  
address list is [’’, ‘localhost’]. It is that ‘’  
that returns uri from other localhost’s ports or other machines in my  
network, somewhat in a non deterministic order, thus primary is non  
deterministic. I tried to find out what this mean and it  
seems to bring me to the topic of socket itself, which I’m not familiar  
with.

Now, if the default broadcast address list is reversed, that is  
‘localhost’ is the first address, then you’ll always get the same  
primary (from my quick, loosely test). Any idea why it is set up as it  
is?

Thanks again for the solution  
-andre

---

<div class="post-metadata">

**Author:** ![andreas](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/ee7513/32.png) [@andreas](https://www.ruby-forum.com/u/andreas)\
**Post date:** [September 10, 2008, 12:21am UTC](https://www.ruby-forum.com/t/rinda-random-econnrefused-error/148080/4 "2008-09-10T00:21:15Z")

</div>

Andreas Sun wrote:

> > I always end up using:
> > 
> > finger=Rinda::RingFinger.new([BROADCAST\_ADDRESS])
> > 
> > remote\_tuplespace=finger.lookup\_ring\_any
> > 
> > for the client and service code…
> 
> This seems works. Thank you.
> 
> You’ve got me looked at the RingFinger class. The default broadcast  
> address list is [’’, ‘localhost’]. It is that ‘’  
> that returns uri from other localhost’s ports or other machines in my  
> network, somewhat in a non deterministic order, thus primary is non  
> deterministic. I tried to find out what this mean and it  
> seems to bring me to the topic of socket itself, which I’m not familiar  
> with.
> 
> Now, if the default broadcast address list is reversed, that is  
> ‘localhost’ is the first address, then you’ll always get the same  
> primary (from my quick, loosely test). Any idea why it is set up as it  
> is?
> 
> Thanks again for the solution  
> -andre

I wish I knew for certain…I spent some time looking at it a few months  
back and couldn’t work my way through the sequence of execution with any  
satisfaction.

Through testing I noticed that for my version (Ubuntu 7/Ruby 1.8.6 p36)  
the instance variable @primary wasn’t set unless I forced a call to  
lookup\_ring\_any which then set & returned the primary instance (and so  
the code above).

I could never get the @rings array to populate with any secondary  
servers so I suspect there are some other issues with how broadcasts are  
being processed, not necessarily within the Rinda code but that may be  
possible as well.

If you look at the RingerFinger initialize method, you see that if you  
use nil for the broadcast address ‘localhost’ is used. This lead me to  
conclude that the default for the class variable @@broadcast\_list (i.e.  
[’’, ‘localhost’]) was likely just a stub meant to be  
overridden but I’m willing to admit that there may be implications that  
have escaped me.

In practice, I’ve found that you need to provide a broadcast address if  
you’re actually distributing the services across multiple machines so  
that finger knows which interface to send the broadcast packets to. This  
isn’t terribly limiting if your machines share a LAN segment or VLAN but  
it can require a bit more work at the router/switch level if this isn’t  
the case.

Also worth noting is line 2 in lib/ring.rb:

# Note: Rinda::Ring API is unstable.

My current thinking is that may just be easier to write a simple  
TupleSpace server (or pair) to provide service location and supply their  
addresses in a config file to all service providers and clients  
especially since you would appear to need to provide a minimal  
configuration (the broadcast address) at any rate.

I’ve been testing this approach and it appears to be solid so far…