AMD-Pensando HA Proposal document#206
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| ### Interaction between Bulk Sync and Datapath Sync | ||
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| Due to the scale requirements for DASH the flow table size that needs to be handled during bulk sync can be very large and hence the bulk sync process can take a long time to complete. It is not possible to halt all traffic that would create new flows during this time. Hence the sync mechanism has to handle creation of new flows during bulk sync. It is also possible that there might be changes in the policy that might affect existing flows. The perfect sync mechanism calls for marking different “color”s to flows that are created after the start of bulk sync. The flow table is walked and all flows not the current color are synchronized to the peer. Any flows that are created during the bulk sync phase are inline synchronized via the datapath synchronization path. Other challenges include | ||
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It is also possible that there might be changes in the policy that might affect existing flows. The perfect sync mechanism calls for marking different “color”s to flows that are created after the start of bulk sync.
can different what are the state (color) can we mark for the flow in hardware. can we get specific state listed.
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At any given time during bulk sync, there are flows that are in the bulk sync snapshot and flows that are were created after the bulk sync started. These classes of flows can be differentiated by the "color". Apart from this within the flows that are in the bulk sync snapshot, there are flows that have already been processed and flows that are yet to be processed. It is okay to rely on DP sync for the former (for flow updates) but not for the later. The implementation may need to track this in the state and handle. Will add this to the description.
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| ## State Synchronization | ||
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| State synchronization between the 2 DPUs uses the CNIP IP. All state synchronization happens at the granularity of the DP-VIP and happens from the primary of the DP-VIP towards the secondary. State synchronization happens in 2 stages |
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is the state synchronization happening in stages or in parallel? would be great to clarify this.
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Yes both are happening in parallel. Will state it here explicitly.
| sai_process_flow_sync_message_fn process_flow_sync_message; | ||
| sai_oper_role_status_fn oper_role_status; | ||
| sai_cp_control_message_fn cp_control_message; | ||
| } sai_dash_ha_api_t; |
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can we have sample code how to call these APIs?
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