On Thu, May 12, 2022 at 9:32 AM Dumitru Ceara <[email protected]> wrote: > > On 5/12/22 10:58, Dumitru Ceara wrote: > > On 5/3/22 21:37, Han Zhou wrote: > >> During the process of claiming a VIF port on a chassis, there are > >> multiple SB and local OVSDB updates by ovn-controller, which may trigger > >> ovn-controller recompute, depending on the timing between the completion > >> of SB and local OVSDB updates: > >> > >> After port claiming, ovn-controller sends an update to the local OVSDB > >> to clean the Interface:external_ids:ovn-installed, and also sends an > >> update to the SB DB to update the Port_Binding:chassis. If the local > >> OVSDB update notification comes back before the SB update completes, > >> ovn-controller's SB IDL is still "in transaction" and read-only, but the > >> local Interface update triggers the I-P engine runtime_data node to > >> handle the OVS_interface change, which considers the VIF to be claimed > >> (again) potentially, which requires SB updates while it is not possible > >> at the moment, and so the I-P handler returns failure and the engine > >> aborts, which triggers recompute at the next I-P engine iteration when > >> SB DB is writable. > >> > >> If we are lucky at the above step that the SB update completes before > >> the local OVSDB update is received, ovn-controller would handle the > >> change incrementally (and figures out that the SB Port_Binding chassis > >> is already the current one thus wouldn't reclaim the VIF). But the next > >> step after it completes flow computing for the newly bound VIF it sends > >> another update to the local OVSDB to set the > >> Interface:external_ids:ovn-installed and ovn-installed-ts, while at the > >> same time it also sends an update to the SB DB to set the > >> Port_Binding:up. These two parallel updates would lead to the same > >> situation as the above step and potentially cause ovn-controll > >> recompute. > >> > >> The recompute is very likely to be triggered in production because the > >> SB DB is remote (on central nodes) and has heavier load, which requires > >> longer time to complete the updates than the local OVSDB server. > >> > >> The problem is that the runtime_data's OVS_interface change handler > >> couldn't handle the update of the Interface:external_ids:ovn-installed > >> incrementally, because ovn-controller assumes it could require an SB > >> update that is not possible at the moment. However, the assumption is > >> not true. In fact it shouldn't even care about the change because this > >> external_id:ovn-installed is written by ovn-controller itself and it is > >> write-only (no need to read it as an input for any further processing). > >> > >> So, the idea to fix the problem is to ignore such changes that happen to > >> the "write-only" fields only. OVSDB change tracking provides APIs to > >> check if a specific column is updated, but the difficulty here is that > >> the column external_ids is a k-v map which contains not only the data > >> that ovn-controller can ignore, such as ovn-installed, ovn-installed-ts, > >> but also the data ovn-controller cares about, such as iface-id, > >> iface-id-ver and encap-ip. To solve this problem, we need to know what's > >> changed exactly inside the external_ids map. > >> > >> This patch solves it by introducing a new I-P engine node > >> ovs_interface_shadow to wrap the OVSDB input ovs_interface with an extra > >> copy of the older version of the column external_ids, and replace the > >> input OVS_interface of the runtime_data node. In the change handler of the > >> runtime_data node we evaluates if the change needs to be handled before > >> calling consider_iface_claim(), so in the above scenarios the changes > >> don't need to be handled and won't trigger recompute any more. A test > >> case is also updated to capture this (which is very likely, if not 100%, > >> to fail without the fix). > >> > >> Signed-off-by: Han Zhou <[email protected]> > > > > Hi Han, > > > > Thanks for the fix! > > > > I would add: > > Fixes: 4d3cb42b076b ("binding: Set Logical_Switch_Port.up when all OVS flows are installed.") > > > > I have another tiny comment below. I'm currently rerunning the > > ovn-kuberenetes tests with your patch applied [0] because the run done > > by ovsrobot failed to bring up a cluster [1] and I want to make sure > > we're not breaking anything. > > > > The CI job passed so, with the minor comments addressed: > > Acked-by: Dumitru Ceara <[email protected]> >
Thanks Dumitru. I addressed the minor comments and applied to main and backported to branch-22.03. @Mark Michelson <[email protected]> I added your ack as well based on your earlier statement :) Thanks, Han > > Thanks, > > Dumitru > > > > [0] https://github.com/dceara/ovn/actions/runs/2312210800 > > [1] https://github.com/ovsrobot/ovn/runs/6280999584?check_suite_focus=true#step:9:725 > > > >> --- > >> v2: Add comments that was missing while committing v1. > >> > >> controller/binding.c | 70 ++++++++++++++++++++++++ > >> controller/binding.h | 1 + > >> controller/ovn-controller.c | 105 +++++++++++++++++++++++++++++++++--- > >> tests/ovn-performance.at | 17 ++++++ > >> 4 files changed, 186 insertions(+), 7 deletions(-) > >> > >> diff --git a/controller/binding.c b/controller/binding.c > >> index 7281b0485..0563d9d1e 100644 > >> --- a/controller/binding.c > >> +++ b/controller/binding.c > >> @@ -1907,6 +1907,71 @@ is_iface_in_int_bridge(const struct ovsrec_interface *iface, > >> return false; > >> } > >> > >> +static bool > >> +is_ext_id_changed(const struct smap *a, const struct smap *b, const char *key) > >> +{ > >> + const char *value_a = smap_get(a, key); > >> + const char *value_b = smap_get(b, key); > >> + if ((value_a && !value_b) > >> + || (!value_a && value_b) > >> + || (value_a && value_b && strcmp(value_a, value_b))) { > >> + return true; > >> + } > >> + return false; > >> +} > >> + > >> +/* Check if the change in 'iface_rec' is something we are interested in from > >> + * port binding perspective. Return true if the change needs to be handled, > >> + * otherwise return false. > >> + * > >> + * The 'iface_rec' must be change tracked, i.e. iterator from > >> + * OVSREC_INTERFACE_TABLE_FOR_EACH_TRACKED. */ > >> +static bool > >> +ovs_interface_change_need_handle(const struct ovsrec_interface *iface_rec, > >> + struct shash *iface_table_external_ids_old) > >> +{ > >> + if (ovsrec_interface_is_updated(iface_rec, > >> + OVSREC_INTERFACE_COL_NAME)) { > >> + return true; > >> + } > >> + if (ovsrec_interface_is_updated(iface_rec, > >> + OVSREC_INTERFACE_COL_OFPORT)) { > >> + return true; > >> + } > >> + if (ovsrec_interface_is_updated(iface_rec, > >> + OVSREC_INTERFACE_COL_TYPE)) { > >> + return true; > >> + } > >> + if (ovsrec_interface_is_updated(iface_rec, > >> + OVSREC_INTERFACE_COL_EXTERNAL_IDS)) { > >> + /* Compare the external_ids that we are interested in with the old > >> + * values: > >> + * - iface-id > >> + * - iface-id-ver > >> + * - encap-ip > >> + * For any other changes, such as ovn-installed, ovn-installed-ts, etc, > >> + * we don't need to handle. */ > >> + struct smap *external_ids_old = > >> + shash_find_data(iface_table_external_ids_old, iface_rec->name); > >> + if (!external_ids_old) { > >> + return true; > >> + } > >> + if (is_ext_id_changed(&iface_rec->external_ids, external_ids_old, > >> + "iface-id")) { > >> + return true; > >> + } > >> + if (is_ext_id_changed(&iface_rec->external_ids, external_ids_old, > >> + "iface-id-ver")) { > >> + return true; > >> + } > >> + if (is_ext_id_changed(&iface_rec->external_ids, external_ids_old, > >> + "encap-ip")) { > >> + return true; > >> + } > >> + } > >> + return false; > >> +} > >> + > >> /* Returns true if the ovs interface changes were handled successfully, > >> * false otherwise. > >> */ > >> @@ -2018,6 +2083,11 @@ binding_handle_ovs_interface_changes(struct binding_ctx_in *b_ctx_in, > >> continue; > >> } > >> > >> + if (!ovs_interface_change_need_handle( > >> + iface_rec, b_ctx_in->iface_table_external_ids_old)) { > >> + continue; > >> + } > >> + > >> const char *iface_id = smap_get(&iface_rec->external_ids, "iface-id"); > >> int64_t ofport = iface_rec->n_ofport ? *iface_rec->ofport : 0; > >> if (iface_id && ofport > 0 && > >> diff --git a/controller/binding.h b/controller/binding.h > >> index 430a8d9b1..e49e1ebb6 100644 > >> --- a/controller/binding.h > >> +++ b/controller/binding.h > >> @@ -55,6 +55,7 @@ struct binding_ctx_in { > >> const struct ovsrec_bridge_table *bridge_table; > >> const struct ovsrec_open_vswitch_table *ovs_table; > >> const struct ovsrec_interface_table *iface_table; > >> + struct shash *iface_table_external_ids_old; > >> }; > >> > >> /* Locally relevant port bindings, e.g., VIFs that might be bound locally, > >> diff --git a/controller/ovn-controller.c b/controller/ovn-controller.c > >> index 22b7fa935..649353f7d 100644 > >> --- a/controller/ovn-controller.c > >> +++ b/controller/ovn-controller.c > >> @@ -1042,6 +1042,91 @@ en_ofctrl_is_connected_run(struct engine_node *node, void *data) > >> engine_set_node_state(node, EN_UNCHANGED); > >> } > >> > >> +/* This engine node is to wrap the OVS_interface input and maintain a copy of > >> + * the old version of data for the column external_ids. > >> + * > >> + * There are some special considerations of this engine node: > >> + * 1. It has a single input OVS_interface, and it transparently passes the > >> + * input changes as its own output data to its dependants. So there is no > >> + * processing to OVS_interface changes but simply mark the node status as > >> + * UPDATED (and so the run() and the change handler is the same). > >> + * 2. The iface_table_external_ids_old is computed/updated in the member > >> + * clear_tracked_data(), because that is when the last round of processing > >> + * has completed but the new IDL data is yet to refresh, so we replace the > >> + * old data with the current data. */ > >> +struct ed_type_ovs_interface_shadow { > >> + struct ovsrec_interface_table *iface_table; > >> + struct shash iface_table_external_ids_old; > >> +}; > >> + > >> +static void * > >> +en_ovs_interface_shadow_init(struct engine_node *node OVS_UNUSED, > >> + struct engine_arg *arg OVS_UNUSED) > >> +{ > >> + struct ed_type_ovs_interface_shadow *data = xzalloc(sizeof *data); > >> + data->iface_table = NULL; > >> + shash_init(&data->iface_table_external_ids_old); > >> + > >> + return data; > >> +} > >> + > >> +static void > >> +iface_table_external_ids_old_destroy(struct shash *table_ext_ids) > >> +{ > >> + struct shash_node *node; > >> + SHASH_FOR_EACH_SAFE (node, table_ext_ids) { > >> + struct smap *ext_ids = node->data; > >> + smap_destroy(ext_ids); > > > > Nit: no need for SHASH_FOR_EACH_SAFE as far as I can tell. > > > > > >> + } > >> + shash_destroy_free_data(table_ext_ids); > >> +} > >> + > >> +static void > >> +en_ovs_interface_shadow_cleanup(void *data_) > >> +{ > >> + struct ed_type_ovs_interface_shadow *data = data_; > >> + iface_table_external_ids_old_destroy(&data->iface_table_external_ids_old); > >> +} > >> + > >> +static void > >> +en_ovs_interface_shadow_clear_tracked_data(void *data_) > >> +{ > >> + struct ed_type_ovs_interface_shadow *data = data_; > >> + iface_table_external_ids_old_destroy(&data->iface_table_external_ids_old); > >> + shash_init(&data->iface_table_external_ids_old); > >> + > >> + if (!data->iface_table) { > >> + return; > >> + } > >> + > >> + const struct ovsrec_interface *iface_rec; > >> + OVSREC_INTERFACE_TABLE_FOR_EACH (iface_rec, data->iface_table) { > >> + struct smap *external_ids = xmalloc(sizeof *external_ids); > >> + smap_clone(external_ids, &iface_rec->external_ids); > >> + shash_add(&data->iface_table_external_ids_old, iface_rec->name, > >> + external_ids); > >> + } > >> +} > >> + > >> +static void > >> +en_ovs_interface_shadow_run(struct engine_node *node, void *data_) > >> +{ > >> + struct ed_type_ovs_interface_shadow *data = data_; > >> + struct ovsrec_interface_table *iface_table = > >> + (struct ovsrec_interface_table *)EN_OVSDB_GET( > >> + engine_get_input("OVS_interface", node)); > >> + data->iface_table = iface_table; > >> + engine_set_node_state(node, EN_UPDATED); > >> +} > >> + > >> +static bool > >> +ovs_interface_shadow_ovs_interface_handler(struct engine_node *node, > >> + void *data_) > >> +{ > >> + en_ovs_interface_shadow_run(node, data_); > >> + return true; > >> +} > >> + > >> struct ed_type_runtime_data { > >> /* Contains "struct local_datapath" nodes. */ > >> struct hmap local_datapaths; > >> @@ -1214,9 +1299,8 @@ init_binding_ctx(struct engine_node *node, > >> (struct ovsrec_port_table *)EN_OVSDB_GET( > >> engine_get_input("OVS_port", node)); > >> > >> - struct ovsrec_interface_table *iface_table = > >> - (struct ovsrec_interface_table *)EN_OVSDB_GET( > >> - engine_get_input("OVS_interface", node)); > >> + struct ed_type_ovs_interface_shadow *iface_shadow = > >> + engine_get_input_data("ovs_interface_shadow", node); > >> > >> struct ovsrec_qos_table *qos_table = > >> (struct ovsrec_qos_table *)EN_OVSDB_GET( > >> @@ -1249,7 +1333,9 @@ init_binding_ctx(struct engine_node *node, > >> b_ctx_in->sbrec_port_binding_by_datapath = sbrec_port_binding_by_datapath; > >> b_ctx_in->sbrec_port_binding_by_name = sbrec_port_binding_by_name; > >> b_ctx_in->port_table = port_table; > >> - b_ctx_in->iface_table = iface_table; > >> + b_ctx_in->iface_table = iface_shadow->iface_table; > >> + b_ctx_in->iface_table_external_ids_old = > >> + &iface_shadow->iface_table_external_ids_old; > >> b_ctx_in->qos_table = qos_table; > >> b_ctx_in->port_binding_table = pb_table; > >> b_ctx_in->br_int = br_int; > >> @@ -1331,7 +1417,7 @@ en_runtime_data_run(struct engine_node *node, void *data) > >> } > >> > >> static bool > >> -runtime_data_ovs_interface_handler(struct engine_node *node, void *data) > >> +runtime_data_ovs_interface_shadow_handler(struct engine_node *node, void *data) > >> { > >> struct ed_type_runtime_data *rt_data = data; > >> struct binding_ctx_in b_ctx_in; > >> @@ -3338,6 +3424,8 @@ main(int argc, char *argv[]) > >> > >> /* Define inc-proc-engine nodes. */ > >> ENGINE_NODE_WITH_CLEAR_TRACK_DATA_IS_VALID(ct_zones, "ct_zones"); > >> + ENGINE_NODE_WITH_CLEAR_TRACK_DATA(ovs_interface_shadow, > >> + "ovs_interface_shadow"); > >> ENGINE_NODE_WITH_CLEAR_TRACK_DATA(runtime_data, "runtime_data"); > >> ENGINE_NODE(non_vif_data, "non_vif_data"); > >> ENGINE_NODE(mff_ovn_geneve, "mff_ovn_geneve"); > >> @@ -3459,6 +3547,9 @@ main(int argc, char *argv[]) > >> engine_add_input(&en_ct_zones, &en_runtime_data, > >> ct_zones_runtime_data_handler); > >> > >> + engine_add_input(&en_ovs_interface_shadow, &en_ovs_interface, > >> + ovs_interface_shadow_ovs_interface_handler); > >> + > >> engine_add_input(&en_runtime_data, &en_ofctrl_is_connected, NULL); > >> > >> engine_add_input(&en_runtime_data, &en_ovs_open_vswitch, NULL); > >> @@ -3480,8 +3571,8 @@ main(int argc, char *argv[]) > >> */ > >> engine_add_input(&en_runtime_data, &en_ovs_port, > >> engine_noop_handler); > >> - engine_add_input(&en_runtime_data, &en_ovs_interface, > >> - runtime_data_ovs_interface_handler); > >> + engine_add_input(&en_runtime_data, &en_ovs_interface_shadow, > >> + runtime_data_ovs_interface_shadow_handler); > >> > >> engine_add_input(&en_flow_output, &en_lflow_output, > >> flow_output_lflow_output_handler); > >> diff --git a/tests/ovn-performance.at b/tests/ovn-performance.at > >> index bc133f93b..9affca498 100644 > >> --- a/tests/ovn-performance.at > >> +++ b/tests/ovn-performance.at > >> @@ -366,6 +366,23 @@ for i in 1 2; do > >> ovn-nbctl wait-until Logical_Switch_Port $lp 'up=true' && > >> ovn-nbctl --wait=hv sync] > >> ) > >> + > >> + # Delete and recreate $lp to make it unbind and rebind multiple times, and > >> + # ensure no recompute is triggered. > >> + for k in $(seq 10); do > >> + OVN_CONTROLLER_EXPECT_NO_HIT( > >> + [hv$i hv$j], [lflow_run], > >> + [as hv$i ovs-vsctl set Interface $vif external-ids:iface-id=xxxx && > >> + ovn-nbctl wait-until Logical_Switch_Port $lp 'up=false' && > >> + ovn-nbctl --wait=hv sync] > >> + ) > >> + OVN_CONTROLLER_EXPECT_NO_HIT( > >> + [hv$i hv$j], [lflow_run], > >> + [as hv$i ovs-vsctl set Interface $vif external-ids:iface-id=$lp && > >> + ovn-nbctl wait-until Logical_Switch_Port $lp 'up=true' && > >> + ovn-nbctl --wait=hv sync] > >> + ) > >> + done > >> done > >> > >> for i in 1 2; do > > > _______________________________________________ dev mailing list [email protected] https://mail.openvswitch.org/mailman/listinfo/ovs-dev
