Re: [ovs-discuss] Flow miss/Packet order question
It isn't commonly a problem in practice because flows most often start off with a single packet and wait for a return packet before ramping up packet volume. I've been aware of the issue for years, but you are the only other person I ever recall bringing it up on the mailing lists. Do you have a real situation (not a hypothetical scenario) where you see this causing trouble? On Fri, Apr 27, 2012 at 11:06:29AM +0600, junaid khalid wrote: > Are you planning to solve this problem in near future or do you have any > suggestions to mitigate this problem? > > On Thu, Apr 26, 2012 at 2:37 AM, Ben Pfaff wrote: > > > On Wed, Apr 25, 2012 at 01:33:56PM -0700, Joji Mtt wrote: > > > I am trying to figure out if there would be a packet order issue with the > > > current version of OVS. Consider a case where a controller has added a > > > forwarding rule for a specific flow (Flow A) and this rule is not yet > > > installed in the DP. In this scenario, it is conceivable that certain > > > (bursty) traffic patterns on Flow A can result in the packets being sent > > > out of order. E.g. consider an initial burst of 5 packets that miss the > > > kernel flow table, followed by several subsequent packets arriving at > > > random intervals. As soon as the userspace processes the flow miss, it > > will > > > install a rule in the kernel. Depending on the relative timing of the > > rule > > > installation, any of these subsequent packets could get switched directly > > > by the kernel before the previous packets that took the slow path could > > get > > > forwarded. I couldn't find any special handling to cover this case. Most > > > likely it is already handled and I am just missing the part where it is > > > done. Could anyone clarify this for me? > > > > Yes, it's possible to get out-of-order packets for this reason. > > ___ > > discuss mailing list > > discuss@openvswitch.org > > http://openvswitch.org/mailman/listinfo/discuss > > ___ discuss mailing list discuss@openvswitch.org http://openvswitch.org/mailman/listinfo/discuss
Re: [ovs-discuss] Flow miss/Packet order question
Are you planning to solve this problem in near future or do you have any suggestions to mitigate this problem? On Thu, Apr 26, 2012 at 2:37 AM, Ben Pfaff wrote: > On Wed, Apr 25, 2012 at 01:33:56PM -0700, Joji Mtt wrote: > > I am trying to figure out if there would be a packet order issue with the > > current version of OVS. Consider a case where a controller has added a > > forwarding rule for a specific flow (Flow A) and this rule is not yet > > installed in the DP. In this scenario, it is conceivable that certain > > (bursty) traffic patterns on Flow A can result in the packets being sent > > out of order. E.g. consider an initial burst of 5 packets that miss the > > kernel flow table, followed by several subsequent packets arriving at > > random intervals. As soon as the userspace processes the flow miss, it > will > > install a rule in the kernel. Depending on the relative timing of the > rule > > installation, any of these subsequent packets could get switched directly > > by the kernel before the previous packets that took the slow path could > get > > forwarded. I couldn't find any special handling to cover this case. Most > > likely it is already handled and I am just missing the part where it is > > done. Could anyone clarify this for me? > > Yes, it's possible to get out-of-order packets for this reason. > ___ > discuss mailing list > discuss@openvswitch.org > http://openvswitch.org/mailman/listinfo/discuss > ___ discuss mailing list discuss@openvswitch.org http://openvswitch.org/mailman/listinfo/discuss
Re: [ovs-discuss] OpenStack Quantum plugins
Thanks Justin. I have posted the questions there as well, but since most of the questions are related to OVS I thought people here can also help me understand its functionality. Thanks, Salman > Subject: Re: [ovs-discuss] OpenStack Quantum plugins > From: jpet...@nicira.com > Date: Thu, 26 Apr 2012 14:24:46 -0700 > CC: discuss@openvswitch.org > To: salma...@live.com > > Hi, Salman. There are a few OpenStack/Quantum people on this list, but I > suspect you'll have better luck on the main OpenStack list: > > openst...@lists.launchpad.net > > --Justin > > > On Apr 26, 2012, at 2:07 PM, Salman Malik wrote: > > > > > Hi All, > > > > I am trying to learn the functionality of Quantum plugins used in > > OpenStack. I have read through the Quantum Admin Guide and had few > > basic/quick question about quantum and OVS interaction with it : > > > > > > 1) OVS can have ports in which vNICS can be plugged, so why does it need to > > use an integration bridge for connecting all VMs on the same node to a > > network? > > > > 2) The OVS quantum plugin seems to implement the core API functions and > > (viewing the code) I concluded that it just makes maintains the logical > > mappings e.g. b/w net IDs and VLAN IDs in a database. So how is this > > mapping implemented on the actual ports of OVS? Is it the OVS quantum agent > > responsible for directing the packets to correct input/output ports based > > on the updates that it gets from the database? > > > > 3) The quantum admin guide says that the nova client will be the main user > > of quantum and will interact with it via REST API, so it would be nice if > > someone can point me to the code (file path name etc.) where this happens. > > > > Thanks, > > Salman > > > > PS: What is the purpose of Quantum Manager in this architecture and where > > should I look for its code? > > ___ > > discuss mailing list > > discuss@openvswitch.org > > http://openvswitch.org/mailman/listinfo/discuss > ___ discuss mailing list discuss@openvswitch.org http://openvswitch.org/mailman/listinfo/discuss
Re: [ovs-discuss] OpenStack Quantum plugins
Hi, Salman. There are a few OpenStack/Quantum people on this list, but I suspect you'll have better luck on the main OpenStack list: openst...@lists.launchpad.net --Justin On Apr 26, 2012, at 2:07 PM, Salman Malik wrote: > > Hi All, > > I am trying to learn the functionality of Quantum plugins used in OpenStack. > I have read through the Quantum Admin Guide and had few basic/quick question > about quantum and OVS interaction with it : > > > 1) OVS can have ports in which vNICS can be plugged, so why does it need to > use an integration bridge for connecting all VMs on the same node to a > network? > > 2) The OVS quantum plugin seems to implement the core API functions and > (viewing the code) I concluded that it just makes maintains the logical > mappings e.g. b/w net IDs and VLAN IDs in a database. So how is this mapping > implemented on the actual ports of OVS? Is it the OVS quantum agent > responsible for directing the packets to correct input/output ports based on > the updates that it gets from the database? > > 3) The quantum admin guide says that the nova client will be the main user of > quantum and will interact with it via REST API, so it would be nice if > someone can point me to the code (file path name etc.) where this happens. > > Thanks, > Salman > > PS: What is the purpose of Quantum Manager in this architecture and where > should I look for its code? > ___ > discuss mailing list > discuss@openvswitch.org > http://openvswitch.org/mailman/listinfo/discuss ___ discuss mailing list discuss@openvswitch.org http://openvswitch.org/mailman/listinfo/discuss
[ovs-discuss] OpenStack Quantum plugins
Hi All, I am trying to learn the functionality of Quantum plugins used in OpenStack. I have read through the Quantum Admin Guide and had few basic/quick question about quantum and OVS interaction with it : 1) OVS can have ports in which vNICS can be plugged, so why does it need to use an integration bridge for connecting all VMs on the same node to a network? 2) The OVS quantum plugin seems to implement the core API functions and (viewing the code) I concluded that it just makes maintains the logical mappings e.g. b/w net IDs and VLAN IDs in a database. So how is this mapping implemented on the actual ports of OVS? Is it the OVS quantum agent responsible for directing the packets to correct input/output ports based on the updates that it gets from the database? 3) The quantum admin guide says that the nova client will be the main user of quantum and will interact with it via REST API, so it would be nice if someone can point me to the code (file path name etc.) where this happens. Thanks, Salman PS: What is the purpose of Quantum Manager in this architecture and where should I look for its code? ___ discuss mailing list discuss@openvswitch.org http://openvswitch.org/mailman/listinfo/discuss
Re: [ovs-discuss] Manager
On Thu, Apr 26, 2012 at 03:18:02PM +0300, Sergio Kviato wrote: > What is concept Manager in OVS? A "Manager" is a connection between ovsdb-server and some remote process (the manager). A manager can monitor and update OVS configuration. ___ discuss mailing list discuss@openvswitch.org http://openvswitch.org/mailman/listinfo/discuss
[ovs-discuss] Manager
Hello, What is concept Manager in OVS? Thanks. ___ discuss mailing list discuss@openvswitch.org http://openvswitch.org/mailman/listinfo/discuss
