Question about load balance

On 06/07/2012 10:26 PM, Condor wrote:

Hello ppl,

I read in internet and in this mailing list, when some one asking
about load balance,
most of the answers is: pgpool.
I want to asking how stable is pgpool ? How much query can handle ?
What load average ?
Im looking for something multi master solution.

PgPool-II doesn't offer mutli-master operation. Not much does.

Multi-master is very difficult to get right, and even harder to make fast.

Are you really sure it's what you want? Failover is often a much, MUCH
simpler and more efficient approach.

--
Craig Ringer

Am 08.06.2012 00:39, schrieb Craig Ringer:

On 06/07/2012 10:26 PM, Condor wrote:

Hello ppl,

I read in internet and in this mailing list, when some one asking
about load balance,
most of the answers is: pgpool.
I want to asking how stable is pgpool ? How much query can handle ?
What load average ?
Im looking for something multi master solution.

PgPool-II doesn't offer mutli-master operation. Not much does.

Multi-master is very difficult to get right, and even harder to make
fast.

Are you really sure it's what you want? Failover is often a much, MUCH
simpler and more efficient approach.

--
Craig Ringer

The only multimaster replication solution for PostgreSQL I know of, is
Bucardo.
http://bucardo.org/wiki/Bucardo
Though I second what Craig Ringer wisely says; it's difficult to get it
right and fast.
Best Regards.

http://pglearn.blogspot.mx/
twitter: @sqlhotfix

On 2012-06-08 08:39, Craig Ringer wrote:

On 06/07/2012 10:26 PM, Condor wrote:

Hello ppl,

I read in internet and in this mailing list, when some one asking
about load balance,
most of the answers is: pgpool.
I want to asking how stable is pgpool ? How much query can handle ?
What load average ?
Im looking for something multi master solution.

PgPool-II doesn't offer mutli-master operation. Not much does.

Multi-master is very difficult to get right, and even harder to make
fast.

Are you really sure it's what you want? Failover is often a much,
MUCH simpler and more efficient approach.

--
Craig Ringer

No,
Im not sure, just looking how to make load balance. I have a small
database around 20 gb,
but I expect to join another database on different scheme and Im
looking for solution
about load balance or some cache mechanism. Bad part is one row from db
is read once
in a month, in worst scenario 3-4 times in month and I think cache is
not good option,
but I don't have idea how will work.

H.

On 06/10/12 11:26 PM, Condor wrote:

Im not sure, just looking how to make load balance. I have a small
database around 20 gb,
but I expect to join another database on different scheme and Im
looking for solution
about load balance or some cache mechanism. Bad part is one row from
db is read once
in a month, in worst scenario 3-4 times in month and I think cache is
not good option,
but I don't have idea how will work.

whats the problem you're trying to solve? so far, doesn't sound like
you have anything that a decent database server couldn't handle easily.

--
john r pierce N 37, W 122
santa cruz ca mid-left coast

On 2012-06-11 09:35, John R Pierce wrote:

On 06/10/12 11:26 PM, Condor wrote:

Im not sure, just looking how to make load balance. I have a small
database around 20 gb,
but I expect to join another database on different scheme and Im
looking for solution
about load balance or some cache mechanism. Bad part is one row from
db is read once
in a month, in worst scenario 3-4 times in month and I think cache
is not good option,
but I don't have idea how will work.

whats the problem you're trying to solve? so far, doesn't sound
like you have anything that a decent database server couldn't handle
easily.

--
john r pierce N 37, W 122
santa cruz ca mid-left coast

Maybe my fault that I have divided the issues into two separate e-mail,
one for load balance and one bound by rules on how to bind together
two bases of different schemes.
As I wrote my base is small, and the server keeps a small load average,
but if bind together the two databases since
both must use the recording and reading 3-4 tables only, I seek advice
if the server load is too much what I could do to it landed.
If I run load balance with pgpool how stable will be my system, I run
stream replication but I see when master send data to
slave and in this time I query slave server, slave server break query.
Did I will have same problems with pgpool.
Basically I want to be prepared what options I have if this happens.

H.

On 06/11/12 12:11 AM, Condor wrote:

I seek advice if the server load is too much what I could do to it
landed.

I recommend a faster server for this. more CPU cores, more memory,
faster storage. that will take you a LONG ways, much simpler than
complex and fragile database cluster schemes

--
john r pierce N 37, W 122
santa cruz ca mid-left coast

On 2012-06-11 10:23, John R Pierce wrote:

On 06/11/12 12:11 AM, Condor wrote:

I seek advice if the server load is too much what I could do to it
landed.

I recommend a faster server for this. more CPU cores, more memory,
faster storage. that will take you a LONG ways, much simpler than
complex and fragile database cluster schemes

--
john r pierce N 37, W 122
santa cruz ca mid-left coast

Yes, I now but these parameters can't be increase forever. It's can but
isn't cheep.
For that reason I looking some other ways.

H.

On 06/11/12 2:11 AM, Condor wrote:

Yes, I now but these parameters can't be increase forever. It's can
but isn't cheep.
For that reason I looking some other ways.

why don't you worry about that when you get there, rather than before
you even start?

I've got a 2U dual xeon X5660 server w/ 48GB ram, and built in 20 x 15k
raid10 that can handle like 5000 TPS-C style transactions/second,
(pg_bench). these are update transactions.

--
john r pierce N 37, W 122
santa cruz ca mid-left coast

On 2012-06-11 21:03, John R Pierce wrote:

On 06/11/12 2:11 AM, Condor wrote:

Yes, I now but these parameters can't be increase forever. It's can
but isn't cheep.
For that reason I looking some other ways.

why don't you worry about that when you get there, rather than before
you even start?

May be because some times when some one start a new business does not
have 20k $ for
a new server and resource of the server is enough for the moment and as
I planed
is enough for this year. My question was how stable is pgpool, what
problems I can
expect, and pure curiosity what is the technique for managing large
databases.
CPU and memory to the second coming or are there other techniques for
scattering
applications on other servers.

I've got a 2U dual xeon X5660 server w/ 48GB ram, and built in 20 x
15k raid10 that can handle like 5000 TPS-C style transactions/second,
(pg_bench). these are update transactions.

--
john r pierce N 37, W 122
santa cruz ca mid-left coast

H.

On 06/11/12 12:17 PM, Condor wrote:

May be because some times when some one start a new business does not
have 20k $ for
a new server and resource of the server is enough for the moment and
as I planed
is enough for this year.

and when you start a new business, you don't lease a campus large enough
for 10,000 employees, you deal with that when you need it.

if your app actually ends up needing to scale to google size, plan on
having to redesign it a few times.

--
john r pierce N 37, W 122
santa cruz ca mid-left coast

On Tue, Jun 12, 2012 at 5:17 AM, Condor <condor@stz-bg.com> wrote:

On 2012-06-11 21:03, John R Pierce wrote:

On 06/11/12 2:11 AM, Condor wrote:

Yes, I now but these parameters can't be increase forever. It's can but
isn't cheep.
For that reason I looking some other ways.

why don't you worry about that when you get there, rather than before
you even start?

May be because some times when some one start a new business does not have
20k $ for
a new server and resource of the server is enough for the moment and as I
planed

Postgres performance is pretty awesome even on a cheap laptop. I've
done thrash testing on a basic unit that forms the backbone of our
dev/test system, and also on a similar laptop that has a couple
hundred dollars of SSD replacing its standard hard drive, and both of
them can handle more TPS than you would think to look at them. (I
don't actually have database-level TPS ratings for them, but they
managed 5-10K items per second of conceptual throughput - each "item"
involving quite a bit of processing.) Put it onto some real server
hardware, even just $1K or so, and you'll have something that you can
upgrade for as long as you need to.

ChrisA

On 2012-06-11 22:47, John R Pierce wrote:

On 06/11/12 12:17 PM, Condor wrote:

May be because some times when some one start a new business does
not have 20k $ for
a new server and resource of the server is enough for the moment and
as I planed
is enough for this year.

and when you start a new business, you don't lease a campus large
enough for 10,000 employees, you deal with that when you need it.

if your app actually ends up needing to scale to google size, plan on
having to redesign it a few times.

--
john r pierce N 37, W 122
santa cruz ca mid-left coast

--- cut ---
My question was how stable is pgpool, what problems I can
expect, and pure curiosity what is the technique for managing large 
databases.
CPU and memory to the second coming or are there other techniques for 
scattering
  applications on other servers.

--- cut ---

I think I'm trying to learn information what is the technique for
managing large databases
not to philosophize what was my server.

H.

My question was how stable is pgpool, what problems I can
expect, and pure curiosity what is the technique for managing large
databases.
CPU and memory to the second coming or are there other techniques for
scattering
applications on other servers.

--- cut ---

I think I'm trying to learn information what is the technique for
managing large databases
not to philosophize what was my server.

You'd better to subscribe pgpool-general@pgpool.net list
(http://www.pgpool.net/mediawiki/index.php/Mailing_lists) and post
this kind of question. There are many people who are serious about
pgpool in the list.
--
Tatsuo Ishii
SRA OSS, Inc. Japan
English: http://www.sraoss.co.jp/index_en.php
Japanese: http://www.sraoss.co.jp

Hi,

I think I'm trying to learn information what is the technique for managing
large databases
not to philosophize what was my server.

In this case it starts to get very specific about what you are trying
to accomplish.
Transactional databases offer a lot guarantees, which makes it hard to
"just add another machine to the cluster", this isn't a webserver ;)

- Clemens

On 06/11/12 11:29 PM, Condor wrote:

I think I'm trying to learn information what is the technique for
managing large databases
not to philosophize what was my server.

you handle large databases with a lot of fast disk, and memory, this
gets you into the terabytes.

clustering/load balancing would not do for this, other than needing MORE
fast disk (N replicas require N times the disk system of one
database). clustering can provide active/slave failover for high
availability, or it can provide replicas for balancing read queries.
updates have to be made to all the replicas, so they wont be any faster
than a single server (in fact, will be slower due to the overhead of
replication

--
john r pierce N 37, W 122
santa cruz ca mid-left coast

On 2012-06-12 10:48, John R Pierce wrote:

On 06/11/12 11:29 PM, Condor wrote:

I think I'm trying to learn information what is the technique for
managing large databases
not to philosophize what was my server.

you handle large databases with a lot of fast disk, and memory, this
gets you into the terabytes.

clustering/load balancing would not do for this, other than needing
MORE fast disk (N replicas require N times the disk system of one
database). clustering can provide active/slave failover for high
availability, or it can provide replicas for balancing read queries.
updates have to be made to all the replicas, so they wont be any
faster than a single server (in fact, will be slower due to the
overhead of replication

--
john r pierce N 37, W 122
santa cruz ca mid-left coast

Thanks, I thought so, but I was not sure whether this is a better
option.

H.