From: Rick James
Date: July 16 2012 4:56pm
Subject: RE: mysql - uppoer limit for doing simultaneous red/writes..
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What does "simultaneous connection" mean?  1000 open connections is reasona=
ble; 10 _active_ connections is reasonable; 1000-10000 queries/second may b=
e reasonable.

If these are readonly connections, then you could set up any number of Slav=
es.  100 Slaves with 1000 connections each would achieve 100K "simultaneous=
 connections"?

By "writes" do you mean INSERTs?  Or UPDATEs?  Or DELETEs?

Regular disks cannot handle more than 100 I/Os per second.  RAID, SSD, etc =
can help some.  But it is essentially impossible (due to I/O) to do more th=
an 1K _random_ writes per second.

Describe your application further; there may be ways to make it work.

Is this a web app?  Web connections cannot (and should not) be persistent. =
 If you have 2000 Apache servers, each with MaxClients=3D25, that is 50K "c=
onnections" from the user's point of view.  But the connections to MySQL ca=
n (should) come and go rapidly enough so there may not be an issue.

Please estimate "queries per second", and "writes per second", not "simulta=
neous connections".

> -----Original Message-----
> From: Reindl Harald [mailto:h.reindl@stripped]
> Sent: Saturday, July 14, 2012 11:19 AM
> To: mysql@stripped
> Subject: Re: mysql - uppoer limit for doing simultaneous red/writes..
>=20
>=20
>=20
> Am 14.07.2012 19:16, schrieb bruce:
> > Hi.
> >
> > Considering a system, where I have a centralized Mysql setup. I'm not
> > sure exactly what this should be called, single box, cluster, etc...
> >
> > But I'm looking to have a system of a a bunch of boxes, whihc run
> apps
> > that will access (read/write) to the different dbs/tbls on the mysql
> > setup.
> >
> > I'm trying to get a feel for just what mysql can handle in this
> situation.
> >
> > Can a mysql setup handle 50K-100K simultaneous connections
> > (reads/writes) to the same db..
>=20
> simply no
>=20
> you need around 1-2 MB per connection memory besides locking, IOPS and
> other scale troubles
>=20
> you would nee at least 35-50 GB RAM for this
>=20
> but however, 50k connections are not realistic from where should they
> come? mysqld would be not the only bottenleck