hi, Thank you for your reply. I have do some expriment following your adivce. It seems that add 8 or 50 ports a time may reach the high performance, the performance will reduce if we add more than 50 ports a time. (expriment result: total 4000 ports, 4 ports a time, takes 977 seconds, and 8 ports a time, takes 622 seconds, 50 ports a time, takes 373 seconds, and 100 ports a time, takes 400 seconds) If I add 16K ports, then reload the vswitchd and ovsdb, it only takes about 10+ minutes. So I think it is adding port to database takes the most time, and it has become the bottle neck. Here is the question: 1. why in function ovsdb_idl_txn_commit() need the operation wait? 2. do you have any documents about ovsdb mechanism?
At 2014-08-09 02:53:16, "Gurucharan Shetty" <[email protected]> wrote: >On Wed, Aug 6, 2014 at 11:41 PM, ychen <[email protected]> wrote: >> hi: >> i have encountered a problem that ovs add-port takes long time, can you >> help me? >> testing enviroment: >> CentOS release 6.5 (Final), >> Linux l3vpn2 3.16.0-rc1 #1 SMP Mon Jun 16 15:45:19 EDT 2014 x86_64 x86_64 >> x86_64 GNU/Linux >> ovs-vswitchd (Open vSwitch) 1.11.0 >> Compiled Jul 30 2013 18:14:54 >> OpenFlow versions 0x1:0x1 >> >> testing step: >> 1. add br0 >> 2. use cmd ovs-vsctl add-port, to add 16K internal ports, each 4 ports are >> in the same namespace >> >> problem: >> for the first 100~200 ports, system responds quickly; and then it become >> slower and slower >It is sort of expected and the current behavior. You can speed things >a bit by adding multiple ports with a single ovs-vsctl command >invocation. 50-100 at a time may help. >> after the total port numbers reached to 8000, it takes about 3 minutes to >> add one vport >> >Frankly, anything beyond 5000 ports, you are stressing your system. >ovs-vswitchd has to manage all those ports, so it will be slow. (I >have heard people using 10,000 tunnels (not regular ports) and >apparently that is alright.) > > >> analysis: >> i have read the kernel code, and i don't think it is the reason why ovs >> add-port so slowly >> i doubt whether the ovsdb is the main reason? and how can i fix the problem? >I don't think it is a simple problem to solve. There are many facets >to it. You will have to go through the code of both ovsdb-server and >ovs-vswitchd. > > > >> >> >> >> >> _______________________________________________ >> discuss mailing list >> [email protected] >> http://openvswitch.org/mailman/listinfo/discuss >>
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