Why does ip_hash only use the first 3 octects of the IP address?
The reason I ask is that we run we servers for a number of schools.
Each
school is going the be their own subnet, ranging from a /24 to a /20 in
size. Since ip_hash will lump everyone from a /24 in the same hash, it
will direct them to the same server, correct?
If I am correct above, is there any way to create persistent connections
based on the full IPv4 address?
–
William Brown
Core Hosted Application Technical Team and Messaging Team
Technology Services, WNYRIC, Erie 1 BOCES
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Hello!
On Tue, Feb 05, 2013 at 10:38:35AM -0500, [email protected] wrote:
Why does ip_hash only use the first 3 octects of the IP address?
The reason I ask is that we run we servers for a number of schools. Each
school is going the be their own subnet, ranging from a /24 to a /20 in
size. Since ip_hash will lump everyone from a /24 in the same hash, it
will direct them to the same server, correct?
Yes.
The ip_hash balancing was designed to work with internet services,
and use of /24 networks allows it to keep users from migrating
between backend servers as they get new IP address on
reconnect/reboot (typically from the same /24 network, at least at
the time ip_hash was introduced) while still providing good
distribution between backend servers. This probably isn’t very
useful nowadays, but this is how it works.
If I am correct above, is there any way to create persistent connections
based on the full IPv4 address?
There is a number of 3rd party modules available which do hash
calculation based on arbitrary variables, and these may be used if
you need a hash based on full client’s IPv4 address (there is
$remote_addr variable).
–
Maxim D.
Maxim wrote on 02/06/2013 11:47:22 AM:
The ip_hash balancing was designed to work with internet services,
and use of /24 networks allows it to keep users from migrating
between backend servers as they get new IP address on
reconnect/reboot (typically from the same /24 network, at least at
the time ip_hash was introduced) while still providing good
distribution between backend servers. This probably isn’t very
useful nowadays, but this is how it works.
Thank you for the explanation.
If I am correct above, is there any way to create persistent
connections
based on the full IPv4 address?
There is a number of 3rd party modules available which do hash
calculation based on arbitrary variables, and these may be used if
you need a hash based on full client’s IPv4 address (there is
$remote_addr variable).
The backend I am hoping to use nginx for works fine without persistence,
I
was just thinking it would help with troubleshooting by keeping all of a
user’s activity on one server. That way I would have one log to check.
I
will look into those modules.
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