You have to balance that against the minimal cost of today's
memory (even ECC RAM is under $10 per GiB).
True, RAM is relatively cheap, but servers are not. We like to stack as
many instances of tomcat on a server as possible while maintaining good
performance. Some of our 8-core 32GB
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Eric,
(Late reply. Sorry.)
On 2/17/12 11:41 PM, Robinson, Eric wrote:
Recently, we had someone tell us that a particular thread of one
particular Windows tomcat instance was freezing up due to lack of
memory. They insisted that we set that
From: Christopher Schultz [mailto:ch...@christopherschultz.net]
Subject: Re: Free Memory vs. Total Memory vs. Max Memory
I'll have to do some more reading about the JVM returning memory
to the OS after the heap shrinks: if the JVM does not return the
memory, then your most-recent peak
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Chuck,
On 2/21/12 1:06 PM, Caldarale, Charles R wrote:
From: Christopher Schultz [mailto:ch...@christopherschultz.net]
Subject: Re: Free Memory vs. Total Memory vs. Max Memory
I'll have to do some more reading about the JVM returning memory
From: Christopher Schultz [mailto:ch...@christopherschultz.net]
Subject: Re: Free Memory vs. Total Memory vs. Max Memory
Okay, so it sounds like if the environment is such that reducing the
heap at intervals is important (many JVMs, peak-memory-load events are
rare, etc.) then using Xms
On 17/02/2012 04:58, Robinson, Eric wrote:
What are the possible downsides of setting a low initial memory pool and
a high max pool? If a tomcat app usually needs approximately 64MB of
heap space, but sometimes as much as 300-400MB, would it cause any
problems to set the initial pool to 16M
What are the possible downsides of setting a low initial
memory pool
and a high max pool? If a tomcat app usually needs
approximately 64MB
of heap space, but sometimes as much as 300-400MB, would it
cause any
problems to set the initial pool to 16M and the max pool to 512M?
An
From: Robinson, Eric [mailto:eric.robin...@psmnv.com]
Subject: RE: Free Memory vs. Total Memory vs. Max Memory
If what you described occurs, we would see OOMs in the
logs, correct?
Only rarely. More typical is slow response and annoyed end users.
Also, if the machine has inadequate RAM
Robinson, Eric wrote:
We have many servers that have been running 100-200 instances
of tomcat each for years without any performance problems.
Most of our servers are Linux 8-core machines with 32GB RAM,
with the tomcat instances configured with -Xms16M -Xmx192M.
We also have some Windows
Robinson, Eric wrote:
We have many servers that have been running 100-200 instances of
tomcat each for years without any performance problems.
Most of our servers are Linux 8-core machines with 32GB
RAM, with the
tomcat instances configured with -Xms16M -Xmx192M.
We also have some
Robinson, Eric eric.robin...@psmnv.com wrote:
Agreed. Anyway, in this case the thread is on a tomcat server that is
only used for scheduled java tasks. Users do not access it directly.
Very puzzling. What's I'd really like is for some well-known tomcat
guru
to say that in our environment, -Xms16M
On 18/02/2012 14:44, Mark Thomas wrote:
Robinson, Eric eric.robin...@psmnv.com wrote:
Agreed. Anyway, in this case the thread is on a tomcat server that
is only used for scheduled java tasks. Users do not access it
directly. Very puzzling. What's I'd really like is for some
well-known
Robinson, Eric wrote:
What are the possible downsides of setting a low initial memory pool and
a high max pool? If a tomcat app usually needs approximately 64MB of
heap space, but sometimes as much as 300-400MB, would it cause any
problems to set the initial pool to 16M and the max pool to 512M?
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Eric,
On 2/17/12 3:28 AM, André Warnier wrote:
Robinson, Eric wrote:
What are the possible downsides of setting a low initial memory
pool and a high max pool? If a tomcat app usually needs
approximately 64MB of heap space, but sometimes as much
If your application
needs 64MB of
Heap space and you allocate only -Xms16M, then right at the
start the
JVM will have to increase the Heap to 64MB (minimum); so
why would you
do that ?
64MB was just a number I threw out. The app actually uses about 20MB at
startup, so we might
Note that you are talking of memory pool, which is a bit
vague. The -Xms and -Xmx parameters relate to how big the
Heap is, which is only one part of the memory space needed by the JVM.
I am just using the terms that I see on the screen when I pull up
tomcat6w.exe.
--Eric
Disclaimer
Robinson, Eric wrote:
Note that you are talking of memory pool, which is a bit
vague. The -Xms and -Xmx parameters relate to how big the
Heap is, which is only one part of the memory space needed by the JVM.
I am just using the terms that I see on the screen when I pull up
tomcat6w.exe.
Robinson, Eric wrote:
If your application
needs 64MB of
Heap space and you allocate only -Xms16M, then right at the
start the
JVM will have to increase the Heap to 64MB (minimum); so
why would you
do that ?
64MB was just a number I threw out. The app actually uses about 20MB at
startup,
I can see the lure of only taking what you need and allowing the
JVM to automatically re-size the memory space:
that way, you only take up a huge chunk of memory during peak load
and not all the time.
But why?
If you are going to need, say, 512MiB at peak load, you're
going to
We have many servers that have been running 100-200 instances
of tomcat each for years without any performance problems.
Most of our servers are Linux 8-core machines with 32GB RAM,
with the tomcat instances configured with -Xms16M -Xmx192M.
We also have some Windows servers with 100-150
What are the possible downsides of setting a low initial memory pool and
a high max pool? If a tomcat app usually needs approximately 64MB of
heap space, but sometimes as much as 300-400MB, would it cause any
problems to set the initial pool to 16M and the max pool to 512M?
--
Eric
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