Use the DNS to Announce Your ZeroMQ Services | Hacker News Reader

Use the DNS to Announce Your ZeroMQ Services

ceondo.com

19 pointsLoic10 comments

So.. What exactly is wrong with using SRV records [1] in this case?

1: https://en.wikipedia.org/wiki/SRV_record

In this particular case it is that I want to provide more than just a end point and a port. A JSON string is put in the TXT record to store associated meta data. If you do not need these metadata, SRV record is perfect.

What's wrong with using something like ZooKeeper? In my understanding, master election, storage of configuration data and the likes are what it's made for; and you can have multiple ZK servers that still contain one single configuration database.

It is extremely heavy to setup for just 50 JSON strings to share with 50 to 150 VMs.

https://github.com/lusis/Noah is a much lighter alternative.

Interesting, a service registry in Ruby. If you already have redis etc. running on your system, why not. But as I already have the dns servers running — for my specific use case — you cannot beat it, because it means just one line per service in my DNS server configuration to have it available.

We've actually implemented automatic DNS search withing 0MQ itself. You can then use it like this:

zmq_connect (s, "dns://myservice.example.org");

If people are interested in that, we can upload it to github.

It seems to be available already. Check it out here:

https://github.com/mato/libzmq/tree/dns

Thanks to VMware for sponsoring the feature!

Very nice, it is by the way using a TXT record to store the information. As pointed out before, an SRV record could be better (but only for udp/tcp for the transport mechanism).

https://github.com/mato/libzmq/commit/d2782c7b1c401037718eaf...

Yes, it's using a TXT record precisely so that we can store any endpoint URL. An alternative using SRV records could of course be easily implemented.

The implementation is very much a 1st cut at the moment (no real error handling, no load balancing of multiple records, and the integration of dns.c needs work) and has not been officially announced, will do so on the zeromq-dev list shortly.

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