Hello everybody!!! J
Did any of you know or have configured Kamailio servers in redundant and load distribution mode on geographically dispersed servers. Can you share some ideas how can this be done. I'm thinking about 2 -3 servers that can be used to distribute load and for redundancy as well. Is Kamailio capable of this or this needs to be done on OS level.
Thank you
Roman
Roman,
On 04/10/2011 04:21 PM, roman@dmytriv.com wrote:
Did any of you know or have configured Kamailio servers in redundant and load distribution mode on geographically dispersed servers. Can you share some ideas how can this be done. I’m thinking about 2 -3 servers that can be used to distribute load and for redundancy as well. Is Kamailio capable of this or this needs to be done on OS level.
"Redundant" vs. "load distribution" are two very different goals and are addressed in different ways. Which is the big priority for you?
Redundancy can be done in many ways, from simply having two servers (perhaps with database replication if extensively DB-backed) that the callers roll over on transaction timeout, to SRV records, to HA setups with Heartbeat/Pacemaker/OCF/etc. Sometimes disk-level replication with DRBD is also a part of that, depending on the requirements.
Geographical load distribution is generally done using some sort of selective DNS query answers + low TTLs, or by using a stateless load balancer (less resource utilisation than stateful) to distribute calls across multiple stateful proxies in various places, or by statically assigning customers to chicago.us.sip.myprovider.com.
-- Alex
Alex, thank you for you hints. Load distribution is more of priority to me. I think low TTL might be a solution. But what can be done to keep Kamailio in sync on geographically dispersed servers?
Roman
-----Original Message----- From: Alex Balashov [mailto:abalashov@evaristesys.com] Sent: Sunday, April 10, 2011 8:32 PM To: sr-users@lists.sip-router.org Subject: Re: [SR-Users] Kamailio multihoming
Roman,
On 04/10/2011 04:21 PM, roman@dmytriv.com wrote:
Did any of you know or have configured Kamailio servers in redundant and load distribution mode on geographically dispersed servers. Can you share some ideas how can this be done. I'm thinking about 2 -3 servers that can be used to distribute load and for redundancy as well. Is Kamailio capable of this or this needs to be done on OS level.
"Redundant" vs. "load distribution" are two very different goals and are addressed in different ways. Which is the big priority for you?
Redundancy can be done in many ways, from simply having two servers (perhaps with database replication if extensively DB-backed) that the callers roll over on transaction timeout, to SRV records, to HA setups with Heartbeat/Pacemaker/OCF/etc. Sometimes disk-level replication with DRBD is also a part of that, depending on the requirements.
Geographical load distribution is generally done using some sort of selective DNS query answers + low TTLs, or by using a stateless load balancer (less resource utilisation than stateful) to distribute calls across multiple stateful proxies in various places, or by statically assigning customers to chicago.us.sip.myprovider.com.
-- Alex
On 04/10/2011 08:59 PM, roman@dmytriv.com wrote:
Alex, thank you for you hints. Load distribution is more of priority to me. I think low TTL might be a solution. But what can be done to keep Kamailio in sync on geographically dispersed servers?
Are you talking about database data, or configurations?
The answers vary depending on whether there are two geographically dispersed servers, or more. But short answer:
1) Circular (master-master) database replication;
2) Disk-level replication over network (i.e. DRBD) -- less suitable for the public Internet, but may be workable depending on overall reachability and site-to-site bandwidth quality, in combination with something like GFS.
3) Manual synchronisation of config files and such with rsync, etc.
In general, I would say #1 is simplest. But there aren't many relational databases out there whose replication schemes easily support more than two masters right now.
-
Alex Balashov -
roman＠dmytriv.com