DHCP + mysql
rgrimsha at syr.edu
Mon Mar 19 12:47:25 UTC 2007
What if a local, embedded SQL datastore was used? These have much higher
and might easily replace OMAPI. Less certain but worthy of
consideration is background replication.
Room 203 Machinery Hall
Syracuse, NY 13244
rgrimsha at syr.edu
>>>> dhcp1 at thehobsons.co.uk 3/19/2007 3:29:07 AM >>>
>jgomez at infoweapons.com wrote:
>>Is it possible to use mysql or any database applications instead of
>>dhcpd.leases in keeping a persistent database of leases that has
>Technically, yes; in practice, no.
>AFAIK the ISC server does not have the capability to do this, and I
>seriously doubt that they would be interested in adding it. There are
>two main reasons :
>Appending to a log file is a fast operation, which means you can
>service clients quickly. Updating an SQL database is going to be VERY
>much slower and that would impinge on the ability of the server to
>service client requests in a timely manner. The current server is, I
>believe, single threaded - so if you introduce even a small delay
>into each transaction then you severely restrict the volume of
>transactions you can handle. Internally the ISC server keeps the data
>in hashed lists for quick searching, no SQL database is going to
>match that for query speed.
>It is a requirement of the rfc that all leases must be written to
>permanent store before being offered to a client - thus avoiding the
>possible situation where a lease is offered, the server dies for
>whatever reason, and then the server offers the same lease to another
>client because it doesn't know about the first offer. Again, this is
>very quick for a log file, but quite slow for an SQL database -
>especially when you consider that you must sync a consistent database
>to disk after each and every update. NB - this requirement is one of
>those that is ignored by most other servers, including Microsofts.
>Even if you got around these two problems, ISC do not have
>development staff sitting around looking for things to do and so are
>unlikely to want to put the amount of effort required into what is
>probably a minority feature.
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