| Message ID | 20190708154157.30207-1-nusiddiq@redhat.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [ovs-dev,v2] ovn-northd: Add the option to pause and resume | expand |
Hi Numan, The code changes all look good, but there are a few problems with the documentation. I've noted them down below. On 7/8/19 11:41 AM, nusiddiq@redhat.com wrote: > From: Numan Siddique <nusiddiq@redhat.com> > > This patch adds 3 unixctl socket comments - pause, resume and is-paused. > > Usage: ovs-appctl -t ovn-northd pause/resume/is-paused > > This feature will be useful if the CMS wants to > - deploy OVN DB servers in active/passive mode and > - run ovn-northd on all these nodes and use unix ctl sockets to > connect to the local OVN DB servers. > > On the nodes where OVN Db ovsdb-servers are in passive mode, the local ovn-northds > will process the DB changes and calculate logical flows to be throw out later > because write txns are not allowed by these ovsdb-servers. It results in > unncessary CPU usage. > > With these commands, CMS can pause ovn-northd on these node. A node > which becomes master, can resume the ovn-northd. > > This feature will be useful in ovn-kubernetes if the above deployment model > is chosen. > > Signed-off-by: Numan Siddique <nusiddiq@redhat.com> > --- > v1 -> v2 > ======= > * Addressed the review comments from Ben and add more documentation > about the runtime options added by this patch. > * v1 had an issue - When paused, it was not even waking up to process > the IDL updates. In v2, the main thread, wakes up to process any > IDL updates, but doesn't do any logical flow computations. > > ovn/northd/ovn-northd.8.xml | 48 +++++++++++++++ > ovn/northd/ovn-northd.c | 117 ++++++++++++++++++++++++++++-------- > tests/ovn-northd.at | 38 ++++++++++++ > 3 files changed, 177 insertions(+), 26 deletions(-) > > diff --git a/ovn/northd/ovn-northd.8.xml b/ovn/northd/ovn-northd.8.xml > index e6417220f..0766902db 100644 > --- a/ovn/northd/ovn-northd.8.xml > +++ b/ovn/northd/ovn-northd.8.xml > @@ -70,6 +70,23 @@ > <dd> > Causes <code>ovn-northd</code> to gracefully terminate. > </dd> > + > + <dt><code>pause</code></dt> > + <dd> > + Pauses the ovn-northd operation from processing any Northbound and > + Southbound database changes. > + </dd> > + > + <dt><code>resume</code></dt> > + <dd> > + Resumes the ovn-northd operation to process Northbound and > + Southbound database contents and generate logical flows. > + </dd> > + > + <dt><code>is-paused</code></dt> > + <dd> > + Returns "true" if ovn-northd is currently paused, "false" otherwise. > + </dd> > </dl> > </p> > > @@ -82,6 +99,37 @@ > of <code>ovn-northd</code> will automatically take over. > </p> > > + <h2> Active-Standby with multiple OVN DB servers</h2> > + <p> > + You may run multiple OVN DB servers in an OVN deployment with: > + <ul> > + <li> > + OVN DB servers deployed in active/passive mode with one active > + and multiple passive ovsdb-servers. > + </li> > + > + <li> > + <code>ovn-northd</code> also deployed on all thes nodes "thes" should either be "these" or "the". I'm not sure which you intended. > + using unix ctl sockets to connect to the local OVN DB servers. > + </li> > + </ul> > + </p> > + > + <p> > + In such deployments, the ovn-northds on the passive nodes will process > + the DB changes and calculate logical flows to be throw out later s/throw/thrown/ > + because write txns are not allowed by the passive ovsdb-servers. I think writing out the word "transaction" is preferred over "txn" for documentation. > + It results in unncessary CPU usage. s/unncessary/unnecessary/ > + </p> > + > + <p> > + With the help of runtime management command <code>pause</code>, you can > + pause <code>ovn-northd</code> on these nodes. When a passive node > + becomes master, you can use the runtime management command > + <code>resume</code> to resume the <code>ovn-northd</code> to process the > + DB changes. > + </p> > + > <h1>Logical Flow Table Structure</h1> > > <p> > diff --git a/ovn/northd/ovn-northd.c b/ovn/northd/ovn-northd.c > index 0b0a96a3a..05ddd60e3 100644 > --- a/ovn/northd/ovn-northd.c > +++ b/ovn/northd/ovn-northd.c > @@ -50,6 +50,9 @@ > VLOG_DEFINE_THIS_MODULE(ovn_northd); > > static unixctl_cb_func ovn_northd_exit; > +static unixctl_cb_func ovn_northd_pause; > +static unixctl_cb_func ovn_northd_resume; > +static unixctl_cb_func ovn_northd_is_paused; > > struct northd_context { > struct ovsdb_idl *ovnnb_idl; > @@ -8639,6 +8642,7 @@ main(int argc, char *argv[]) > struct unixctl_server *unixctl; > int retval; > bool exiting; > + bool paused; > > fatal_ignore_sigpipe(); > ovs_cmdl_proctitle_init(argc, argv); > @@ -8653,6 +8657,10 @@ main(int argc, char *argv[]) > exit(EXIT_FAILURE); > } > unixctl_command_register("exit", "", 0, 0, ovn_northd_exit, &exiting); > + unixctl_command_register("pause", "", 0, 0, ovn_northd_pause, &paused); > + unixctl_command_register("resume", "", 0, 0, ovn_northd_resume, &paused); > + unixctl_command_register("is-paused", "", 0, 0, ovn_northd_is_paused, > + &paused); > > daemonize_complete(); > > @@ -8809,32 +8817,49 @@ main(int argc, char *argv[]) > > /* Main loop. */ > exiting = false; > + paused = false; > while (!exiting) { > - struct northd_context ctx = { > - .ovnnb_idl = ovnnb_idl_loop.idl, > - .ovnnb_txn = ovsdb_idl_loop_run(&ovnnb_idl_loop), > - .ovnsb_idl = ovnsb_idl_loop.idl, > - .ovnsb_txn = ovsdb_idl_loop_run(&ovnsb_idl_loop), > - .sbrec_ha_chassis_grp_by_name = sbrec_ha_chassis_grp_by_name, > - }; > - > - if (!had_lock && ovsdb_idl_has_lock(ovnsb_idl_loop.idl)) { > - VLOG_INFO("ovn-northd lock acquired. " > - "This ovn-northd instance is now active."); > - had_lock = true; > - } else if (had_lock && !ovsdb_idl_has_lock(ovnsb_idl_loop.idl)) { > - VLOG_INFO("ovn-northd lock lost. " > - "This ovn-northd instance is now on standby."); > - had_lock = false; > - } > - > - if (ovsdb_idl_has_lock(ovnsb_idl_loop.idl)) { > - ovn_db_run(&ctx, sbrec_chassis_by_name, &ovnsb_idl_loop); > - if (ctx.ovnsb_txn) { > - check_and_add_supported_dhcp_opts_to_sb_db(&ctx); > - check_and_add_supported_dhcpv6_opts_to_sb_db(&ctx); > - check_and_update_rbac(&ctx); > + /* unixctl_server_run could modify the value of 'paused'. > + * So store the value in local 'paused_' so that we run > + * 'ovsdb_idl_loop_commit_and_wait() at the end of the loop. */ > + bool paused_ = paused; > + > + if (!paused_) { > + struct northd_context ctx = { > + .ovnnb_idl = ovnnb_idl_loop.idl, > + .ovnnb_txn = ovsdb_idl_loop_run(&ovnnb_idl_loop), > + .ovnsb_idl = ovnsb_idl_loop.idl, > + .ovnsb_txn = ovsdb_idl_loop_run(&ovnsb_idl_loop), > + .sbrec_ha_chassis_grp_by_name = sbrec_ha_chassis_grp_by_name, > + }; > + > + if (!had_lock && ovsdb_idl_has_lock(ovnsb_idl_loop.idl)) { > + VLOG_INFO("ovn-northd lock acquired. " > + "This ovn-northd instance is now active."); > + had_lock = true; > + } else if (had_lock && !ovsdb_idl_has_lock(ovnsb_idl_loop.idl)) { > + VLOG_INFO("ovn-northd lock lost. " > + "This ovn-northd instance is now on standby."); > + had_lock = false; > } > + > + if (ovsdb_idl_has_lock(ovnsb_idl_loop.idl)) { > + ovn_db_run(&ctx, sbrec_chassis_by_name, &ovnsb_idl_loop); > + if (ctx.ovnsb_txn) { > + check_and_add_supported_dhcp_opts_to_sb_db(&ctx); > + check_and_add_supported_dhcpv6_opts_to_sb_db(&ctx); > + check_and_update_rbac(&ctx); > + } > + } > + } else { > + /* ovn-northd is paused > + * - we still want to handle any db updates and update the > + * local IDL. Otherwise, when it is resumed, the local IDL > + * copy will be out of sync. > + * - but we don't want to create any txns. > + * */ > + ovsdb_idl_run(ovnnb_idl_loop.idl); > + ovsdb_idl_run(ovnsb_idl_loop.idl); > } > > unixctl_server_run(unixctl); > @@ -8842,8 +8867,16 @@ main(int argc, char *argv[]) > if (exiting) { > poll_immediate_wake(); > } > - ovsdb_idl_loop_commit_and_wait(&ovnnb_idl_loop); > - ovsdb_idl_loop_commit_and_wait(&ovnsb_idl_loop); > + > + if (!paused_) { > + ovsdb_idl_loop_commit_and_wait(&ovnnb_idl_loop); > + ovsdb_idl_loop_commit_and_wait(&ovnsb_idl_loop); > + } else { > + /* ovn-northd is paused, but we still want to wake up for any db > + * updates. */ > + ovsdb_idl_wait(ovnnb_idl_loop.idl); > + ovsdb_idl_wait(ovnsb_idl_loop.idl); > + } > > poll_block(); > if (should_service_stop()) { > @@ -8868,3 +8901,35 @@ ovn_northd_exit(struct unixctl_conn *conn, int argc OVS_UNUSED, > > unixctl_command_reply(conn, NULL); > } > + > +static void > +ovn_northd_pause(struct unixctl_conn *conn, int argc OVS_UNUSED, > + const char *argv[] OVS_UNUSED, void *pause_) > +{ > + bool *pause = pause_; > + *pause = true; > + > + unixctl_command_reply(conn, NULL); > +} > + > +static void > +ovn_northd_resume(struct unixctl_conn *conn, int argc OVS_UNUSED, > + const char *argv[] OVS_UNUSED, void *pause_) > +{ > + bool *pause = pause_; > + *pause = false; > + > + unixctl_command_reply(conn, NULL); > +} > + > +static void > +ovn_northd_is_paused(struct unixctl_conn *conn, int argc OVS_UNUSED, > + const char *argv[] OVS_UNUSED, void *paused_) > +{ > + bool *paused = paused_; > + if (*paused) { > + unixctl_command_reply(conn, "true"); > + } else { > + unixctl_command_reply(conn, "false"); > + } > +} > diff --git a/tests/ovn-northd.at b/tests/ovn-northd.at > index 62e58fd0e..0dea04edc 100644 > --- a/tests/ovn-northd.at > +++ b/tests/ovn-northd.at > @@ -898,3 +898,41 @@ as northd > OVS_APP_EXIT_AND_WAIT([ovn-northd]) > > AT_CLEANUP > + > +AT_SETUP([ovn -- ovn-northd pause and resume]) > +AT_SKIP_IF([test $HAVE_PYTHON = no]) > +ovn_start > + > +AT_CHECK([test xfalse = x`as northd ovs-appctl -t ovn-northd is-paused`]) > + > +ovn-nbctl ls-add sw0 > + > +OVS_WAIT_UNTIL([ > + ovn-sbctl lflow-list sw0 > + test 0 = $?]) > + > +ovn-nbctl ls-del sw0 > +OVS_WAIT_UNTIL([ > + ovn-sbctl lflow-list sw0 > + test 1 = $?]) > + > +# Now pause the ovn-northd > +as northd ovs-appctl -t ovn-northd pause > +AT_CHECK([test xtrue = x`as northd ovs-appctl -t ovn-northd is-paused`]) > + > +ovn-nbctl ls-add sw0 > + > +# There should be no logical flows for sw0 datapath. > +OVS_WAIT_UNTIL([ > + ovn-sbctl lflow-list sw0 > + test 1 = $?]) > + > +# Now resume ovn-northd > +as northd ovs-appctl -t ovn-northd resume > +AT_CHECK([test xfalse = x`as northd ovs-appctl -t ovn-northd is-paused`]) > + > +OVS_WAIT_UNTIL([ > + ovn-sbctl lflow-list sw0 > + test 0 = $?]) > + > +AT_CLEANUP >
On Mon, Jul 8, 2019 at 11:22 PM Mark Michelson <mmichels@redhat.com> wrote: > Hi Numan, > > The code changes all look good, but there are a few problems with the > documentation. I've noted them down below. > > Oops. Lots of typos and mistakes. Thanks for the review. I corrected them and submitted v3. Thanks Numan On 7/8/19 11:41 AM, nusiddiq@redhat.com wrote: > > From: Numan Siddique <nusiddiq@redhat.com> > > > > This patch adds 3 unixctl socket comments - pause, resume and is-paused. > > > > Usage: ovs-appctl -t ovn-northd pause/resume/is-paused > > > > This feature will be useful if the CMS wants to > > - deploy OVN DB servers in active/passive mode and > > - run ovn-northd on all these nodes and use unix ctl sockets to > > connect to the local OVN DB servers. > > > > On the nodes where OVN Db ovsdb-servers are in passive mode, the local > ovn-northds > > will process the DB changes and calculate logical flows to be throw out > later > > because write txns are not allowed by these ovsdb-servers. It results in > > unncessary CPU usage. > > > > With these commands, CMS can pause ovn-northd on these node. A node > > which becomes master, can resume the ovn-northd. > > > > This feature will be useful in ovn-kubernetes if the above deployment > model > > is chosen. > > > > Signed-off-by: Numan Siddique <nusiddiq@redhat.com> > > --- > > v1 -> v2 > > ======= > > * Addressed the review comments from Ben and add more documentation > > about the runtime options added by this patch. > > * v1 had an issue - When paused, it was not even waking up to process > > the IDL updates. In v2, the main thread, wakes up to process any > > IDL updates, but doesn't do any logical flow computations. > > > > ovn/northd/ovn-northd.8.xml | 48 +++++++++++++++ > > ovn/northd/ovn-northd.c | 117 ++++++++++++++++++++++++++++-------- > > tests/ovn-northd.at | 38 ++++++++++++ > > 3 files changed, 177 insertions(+), 26 deletions(-) > > > > diff --git a/ovn/northd/ovn-northd.8.xml b/ovn/northd/ovn-northd.8.xml > > index e6417220f..0766902db 100644 > > --- a/ovn/northd/ovn-northd.8.xml > > +++ b/ovn/northd/ovn-northd.8.xml > > @@ -70,6 +70,23 @@ > > <dd> > > Causes <code>ovn-northd</code> to gracefully terminate. > > </dd> > > + > > + <dt><code>pause</code></dt> > > + <dd> > > + Pauses the ovn-northd operation from processing any Northbound > and > > + Southbound database changes. > > + </dd> > > + > > + <dt><code>resume</code></dt> > > + <dd> > > + Resumes the ovn-northd operation to process Northbound and > > + Southbound database contents and generate logical flows. > > + </dd> > > + > > + <dt><code>is-paused</code></dt> > > + <dd> > > + Returns "true" if ovn-northd is currently paused, "false" > otherwise. > > + </dd> > > </dl> > > </p> > > > > @@ -82,6 +99,37 @@ > > of <code>ovn-northd</code> will automatically take over. > > </p> > > > > + <h2> Active-Standby with multiple OVN DB servers</h2> > > + <p> > > + You may run multiple OVN DB servers in an OVN deployment with: > > + <ul> > > + <li> > > + OVN DB servers deployed in active/passive mode with one active > > + and multiple passive ovsdb-servers. > > + </li> > > + > > + <li> > > + <code>ovn-northd</code> also deployed on all thes nodes > > "thes" should either be "these" or "the". I'm not sure which you intended. > > > + using unix ctl sockets to connect to the local OVN DB servers. > > + </li> > > + </ul> > > + </p> > > + > > + <p> > > + In such deployments, the ovn-northds on the passive nodes will > process > > + the DB changes and calculate logical flows to be throw out later > > s/throw/thrown/ > > > + because write txns are not allowed by the passive ovsdb-servers. > > I think writing out the word "transaction" is preferred over "txn" for > documentation. > > > + It results in unncessary CPU usage. > > s/unncessary/unnecessary/ > > > + </p> > > + > > + <p> > > + With the help of runtime management command <code>pause</code>, > you can > > + pause <code>ovn-northd</code> on these nodes. When a passive node > > + becomes master, you can use the runtime management command > > + <code>resume</code> to resume the <code>ovn-northd</code> to > process the > > + DB changes. > > + </p> > > + > > <h1>Logical Flow Table Structure</h1> > > > > <p> > > diff --git a/ovn/northd/ovn-northd.c b/ovn/northd/ovn-northd.c > > index 0b0a96a3a..05ddd60e3 100644 > > --- a/ovn/northd/ovn-northd.c > > +++ b/ovn/northd/ovn-northd.c > > @@ -50,6 +50,9 @@ > > VLOG_DEFINE_THIS_MODULE(ovn_northd); > > > > static unixctl_cb_func ovn_northd_exit; > > +static unixctl_cb_func ovn_northd_pause; > > +static unixctl_cb_func ovn_northd_resume; > > +static unixctl_cb_func ovn_northd_is_paused; > > > > struct northd_context { > > struct ovsdb_idl *ovnnb_idl; > > @@ -8639,6 +8642,7 @@ main(int argc, char *argv[]) > > struct unixctl_server *unixctl; > > int retval; > > bool exiting; > > + bool paused; > > > > fatal_ignore_sigpipe(); > > ovs_cmdl_proctitle_init(argc, argv); > > @@ -8653,6 +8657,10 @@ main(int argc, char *argv[]) > > exit(EXIT_FAILURE); > > } > > unixctl_command_register("exit", "", 0, 0, ovn_northd_exit, > &exiting); > > + unixctl_command_register("pause", "", 0, 0, ovn_northd_pause, > &paused); > > + unixctl_command_register("resume", "", 0, 0, ovn_northd_resume, > &paused); > > + unixctl_command_register("is-paused", "", 0, 0, > ovn_northd_is_paused, > > + &paused); > > > > daemonize_complete(); > > > > @@ -8809,32 +8817,49 @@ main(int argc, char *argv[]) > > > > /* Main loop. */ > > exiting = false; > > + paused = false; > > while (!exiting) { > > - struct northd_context ctx = { > > - .ovnnb_idl = ovnnb_idl_loop.idl, > > - .ovnnb_txn = ovsdb_idl_loop_run(&ovnnb_idl_loop), > > - .ovnsb_idl = ovnsb_idl_loop.idl, > > - .ovnsb_txn = ovsdb_idl_loop_run(&ovnsb_idl_loop), > > - .sbrec_ha_chassis_grp_by_name = > sbrec_ha_chassis_grp_by_name, > > - }; > > - > > - if (!had_lock && ovsdb_idl_has_lock(ovnsb_idl_loop.idl)) { > > - VLOG_INFO("ovn-northd lock acquired. " > > - "This ovn-northd instance is now active."); > > - had_lock = true; > > - } else if (had_lock && !ovsdb_idl_has_lock(ovnsb_idl_loop.idl)) > { > > - VLOG_INFO("ovn-northd lock lost. " > > - "This ovn-northd instance is now on standby."); > > - had_lock = false; > > - } > > - > > - if (ovsdb_idl_has_lock(ovnsb_idl_loop.idl)) { > > - ovn_db_run(&ctx, sbrec_chassis_by_name, &ovnsb_idl_loop); > > - if (ctx.ovnsb_txn) { > > - check_and_add_supported_dhcp_opts_to_sb_db(&ctx); > > - check_and_add_supported_dhcpv6_opts_to_sb_db(&ctx); > > - check_and_update_rbac(&ctx); > > + /* unixctl_server_run could modify the value of 'paused'. > > + * So store the value in local 'paused_' so that we run > > + * 'ovsdb_idl_loop_commit_and_wait() at the end of the loop. */ > > + bool paused_ = paused; > > + > > + if (!paused_) { > > + struct northd_context ctx = { > > + .ovnnb_idl = ovnnb_idl_loop.idl, > > + .ovnnb_txn = ovsdb_idl_loop_run(&ovnnb_idl_loop), > > + .ovnsb_idl = ovnsb_idl_loop.idl, > > + .ovnsb_txn = ovsdb_idl_loop_run(&ovnsb_idl_loop), > > + .sbrec_ha_chassis_grp_by_name = > sbrec_ha_chassis_grp_by_name, > > + }; > > + > > + if (!had_lock && ovsdb_idl_has_lock(ovnsb_idl_loop.idl)) { > > + VLOG_INFO("ovn-northd lock acquired. " > > + "This ovn-northd instance is now active."); > > + had_lock = true; > > + } else if (had_lock && > !ovsdb_idl_has_lock(ovnsb_idl_loop.idl)) { > > + VLOG_INFO("ovn-northd lock lost. " > > + "This ovn-northd instance is now on standby."); > > + had_lock = false; > > } > > + > > + if (ovsdb_idl_has_lock(ovnsb_idl_loop.idl)) { > > + ovn_db_run(&ctx, sbrec_chassis_by_name, > &ovnsb_idl_loop); > > + if (ctx.ovnsb_txn) { > > + check_and_add_supported_dhcp_opts_to_sb_db(&ctx); > > + check_and_add_supported_dhcpv6_opts_to_sb_db(&ctx); > > + check_and_update_rbac(&ctx); > > + } > > + } > > + } else { > > + /* ovn-northd is paused > > + * - we still want to handle any db updates and update > the > > + * local IDL. Otherwise, when it is resumed, the local > IDL > > + * copy will be out of sync. > > + * - but we don't want to create any txns. > > + * */ > > + ovsdb_idl_run(ovnnb_idl_loop.idl); > > + ovsdb_idl_run(ovnsb_idl_loop.idl); > > } > > > > unixctl_server_run(unixctl); > > @@ -8842,8 +8867,16 @@ main(int argc, char *argv[]) > > if (exiting) { > > poll_immediate_wake(); > > } > > - ovsdb_idl_loop_commit_and_wait(&ovnnb_idl_loop); > > - ovsdb_idl_loop_commit_and_wait(&ovnsb_idl_loop); > > + > > + if (!paused_) { > > + ovsdb_idl_loop_commit_and_wait(&ovnnb_idl_loop); > > + ovsdb_idl_loop_commit_and_wait(&ovnsb_idl_loop); > > + } else { > > + /* ovn-northd is paused, but we still want to wake up for > any db > > + * updates. */ > > + ovsdb_idl_wait(ovnnb_idl_loop.idl); > > + ovsdb_idl_wait(ovnsb_idl_loop.idl); > > + } > > > > poll_block(); > > if (should_service_stop()) { > > @@ -8868,3 +8901,35 @@ ovn_northd_exit(struct unixctl_conn *conn, int > argc OVS_UNUSED, > > > > unixctl_command_reply(conn, NULL); > > } > > + > > +static void > > +ovn_northd_pause(struct unixctl_conn *conn, int argc OVS_UNUSED, > > + const char *argv[] OVS_UNUSED, void *pause_) > > +{ > > + bool *pause = pause_; > > + *pause = true; > > + > > + unixctl_command_reply(conn, NULL); > > +} > > + > > +static void > > +ovn_northd_resume(struct unixctl_conn *conn, int argc OVS_UNUSED, > > + const char *argv[] OVS_UNUSED, void *pause_) > > +{ > > + bool *pause = pause_; > > + *pause = false; > > + > > + unixctl_command_reply(conn, NULL); > > +} > > + > > +static void > > +ovn_northd_is_paused(struct unixctl_conn *conn, int argc OVS_UNUSED, > > + const char *argv[] OVS_UNUSED, void *paused_) > > +{ > > + bool *paused = paused_; > > + if (*paused) { > > + unixctl_command_reply(conn, "true"); > > + } else { > > + unixctl_command_reply(conn, "false"); > > + } > > +} > > diff --git a/tests/ovn-northd.at b/tests/ovn-northd.at > > index 62e58fd0e..0dea04edc 100644 > > --- a/tests/ovn-northd.at > > +++ b/tests/ovn-northd.at > > @@ -898,3 +898,41 @@ as northd > > OVS_APP_EXIT_AND_WAIT([ovn-northd]) > > > > AT_CLEANUP > > + > > +AT_SETUP([ovn -- ovn-northd pause and resume]) > > +AT_SKIP_IF([test $HAVE_PYTHON = no]) > > +ovn_start > > + > > +AT_CHECK([test xfalse = x`as northd ovs-appctl -t ovn-northd > is-paused`]) > > + > > +ovn-nbctl ls-add sw0 > > + > > +OVS_WAIT_UNTIL([ > > + ovn-sbctl lflow-list sw0 > > + test 0 = $?]) > > + > > +ovn-nbctl ls-del sw0 > > +OVS_WAIT_UNTIL([ > > + ovn-sbctl lflow-list sw0 > > + test 1 = $?]) > > + > > +# Now pause the ovn-northd > > +as northd ovs-appctl -t ovn-northd pause > > +AT_CHECK([test xtrue = x`as northd ovs-appctl -t ovn-northd is-paused`]) > > + > > +ovn-nbctl ls-add sw0 > > + > > +# There should be no logical flows for sw0 datapath. > > +OVS_WAIT_UNTIL([ > > + ovn-sbctl lflow-list sw0 > > + test 1 = $?]) > > + > > +# Now resume ovn-northd > > +as northd ovs-appctl -t ovn-northd resume > > +AT_CHECK([test xfalse = x`as northd ovs-appctl -t ovn-northd > is-paused`]) > > + > > +OVS_WAIT_UNTIL([ > > + ovn-sbctl lflow-list sw0 > > + test 0 = $?]) > > + > > +AT_CLEANUP > > > >
diff --git a/ovn/northd/ovn-northd.8.xml b/ovn/northd/ovn-northd.8.xml index e6417220f..0766902db 100644 --- a/ovn/northd/ovn-northd.8.xml +++ b/ovn/northd/ovn-northd.8.xml @@ -70,6 +70,23 @@ <dd> Causes <code>ovn-northd</code> to gracefully terminate. </dd> + + <dt><code>pause</code></dt> + <dd> + Pauses the ovn-northd operation from processing any Northbound and + Southbound database changes. + </dd> + + <dt><code>resume</code></dt> + <dd> + Resumes the ovn-northd operation to process Northbound and + Southbound database contents and generate logical flows. + </dd> + + <dt><code>is-paused</code></dt> + <dd> + Returns "true" if ovn-northd is currently paused, "false" otherwise. + </dd> </dl> </p> @@ -82,6 +99,37 @@ of <code>ovn-northd</code> will automatically take over. </p> + <h2> Active-Standby with multiple OVN DB servers</h2> + <p> + You may run multiple OVN DB servers in an OVN deployment with: + <ul> + <li> + OVN DB servers deployed in active/passive mode with one active + and multiple passive ovsdb-servers. + </li> + + <li> + <code>ovn-northd</code> also deployed on all thes nodes + using unix ctl sockets to connect to the local OVN DB servers. + </li> + </ul> + </p> + + <p> + In such deployments, the ovn-northds on the passive nodes will process + the DB changes and calculate logical flows to be throw out later + because write txns are not allowed by the passive ovsdb-servers. + It results in unncessary CPU usage. + </p> + + <p> + With the help of runtime management command <code>pause</code>, you can + pause <code>ovn-northd</code> on these nodes. When a passive node + becomes master, you can use the runtime management command + <code>resume</code> to resume the <code>ovn-northd</code> to process the + DB changes. + </p> + <h1>Logical Flow Table Structure</h1> <p> diff --git a/ovn/northd/ovn-northd.c b/ovn/northd/ovn-northd.c index 0b0a96a3a..05ddd60e3 100644 --- a/ovn/northd/ovn-northd.c +++ b/ovn/northd/ovn-northd.c @@ -50,6 +50,9 @@ VLOG_DEFINE_THIS_MODULE(ovn_northd); static unixctl_cb_func ovn_northd_exit; +static unixctl_cb_func ovn_northd_pause; +static unixctl_cb_func ovn_northd_resume; +static unixctl_cb_func ovn_northd_is_paused; struct northd_context { struct ovsdb_idl *ovnnb_idl; @@ -8639,6 +8642,7 @@ main(int argc, char *argv[]) struct unixctl_server *unixctl; int retval; bool exiting; + bool paused; fatal_ignore_sigpipe(); ovs_cmdl_proctitle_init(argc, argv); @@ -8653,6 +8657,10 @@ main(int argc, char *argv[]) exit(EXIT_FAILURE); } unixctl_command_register("exit", "", 0, 0, ovn_northd_exit, &exiting); + unixctl_command_register("pause", "", 0, 0, ovn_northd_pause, &paused); + unixctl_command_register("resume", "", 0, 0, ovn_northd_resume, &paused); + unixctl_command_register("is-paused", "", 0, 0, ovn_northd_is_paused, + &paused); daemonize_complete(); @@ -8809,32 +8817,49 @@ main(int argc, char *argv[]) /* Main loop. */ exiting = false; + paused = false; while (!exiting) { - struct northd_context ctx = { - .ovnnb_idl = ovnnb_idl_loop.idl, - .ovnnb_txn = ovsdb_idl_loop_run(&ovnnb_idl_loop), - .ovnsb_idl = ovnsb_idl_loop.idl, - .ovnsb_txn = ovsdb_idl_loop_run(&ovnsb_idl_loop), - .sbrec_ha_chassis_grp_by_name = sbrec_ha_chassis_grp_by_name, - }; - - if (!had_lock && ovsdb_idl_has_lock(ovnsb_idl_loop.idl)) { - VLOG_INFO("ovn-northd lock acquired. " - "This ovn-northd instance is now active."); - had_lock = true; - } else if (had_lock && !ovsdb_idl_has_lock(ovnsb_idl_loop.idl)) { - VLOG_INFO("ovn-northd lock lost. " - "This ovn-northd instance is now on standby."); - had_lock = false; - } - - if (ovsdb_idl_has_lock(ovnsb_idl_loop.idl)) { - ovn_db_run(&ctx, sbrec_chassis_by_name, &ovnsb_idl_loop); - if (ctx.ovnsb_txn) { - check_and_add_supported_dhcp_opts_to_sb_db(&ctx); - check_and_add_supported_dhcpv6_opts_to_sb_db(&ctx); - check_and_update_rbac(&ctx); + /* unixctl_server_run could modify the value of 'paused'. + * So store the value in local 'paused_' so that we run + * 'ovsdb_idl_loop_commit_and_wait() at the end of the loop. */ + bool paused_ = paused; + + if (!paused_) { + struct northd_context ctx = { + .ovnnb_idl = ovnnb_idl_loop.idl, + .ovnnb_txn = ovsdb_idl_loop_run(&ovnnb_idl_loop), + .ovnsb_idl = ovnsb_idl_loop.idl, + .ovnsb_txn = ovsdb_idl_loop_run(&ovnsb_idl_loop), + .sbrec_ha_chassis_grp_by_name = sbrec_ha_chassis_grp_by_name, + }; + + if (!had_lock && ovsdb_idl_has_lock(ovnsb_idl_loop.idl)) { + VLOG_INFO("ovn-northd lock acquired. " + "This ovn-northd instance is now active."); + had_lock = true; + } else if (had_lock && !ovsdb_idl_has_lock(ovnsb_idl_loop.idl)) { + VLOG_INFO("ovn-northd lock lost. " + "This ovn-northd instance is now on standby."); + had_lock = false; } + + if (ovsdb_idl_has_lock(ovnsb_idl_loop.idl)) { + ovn_db_run(&ctx, sbrec_chassis_by_name, &ovnsb_idl_loop); + if (ctx.ovnsb_txn) { + check_and_add_supported_dhcp_opts_to_sb_db(&ctx); + check_and_add_supported_dhcpv6_opts_to_sb_db(&ctx); + check_and_update_rbac(&ctx); + } + } + } else { + /* ovn-northd is paused + * - we still want to handle any db updates and update the + * local IDL. Otherwise, when it is resumed, the local IDL + * copy will be out of sync. + * - but we don't want to create any txns. + * */ + ovsdb_idl_run(ovnnb_idl_loop.idl); + ovsdb_idl_run(ovnsb_idl_loop.idl); } unixctl_server_run(unixctl); @@ -8842,8 +8867,16 @@ main(int argc, char *argv[]) if (exiting) { poll_immediate_wake(); } - ovsdb_idl_loop_commit_and_wait(&ovnnb_idl_loop); - ovsdb_idl_loop_commit_and_wait(&ovnsb_idl_loop); + + if (!paused_) { + ovsdb_idl_loop_commit_and_wait(&ovnnb_idl_loop); + ovsdb_idl_loop_commit_and_wait(&ovnsb_idl_loop); + } else { + /* ovn-northd is paused, but we still want to wake up for any db + * updates. */ + ovsdb_idl_wait(ovnnb_idl_loop.idl); + ovsdb_idl_wait(ovnsb_idl_loop.idl); + } poll_block(); if (should_service_stop()) { @@ -8868,3 +8901,35 @@ ovn_northd_exit(struct unixctl_conn *conn, int argc OVS_UNUSED, unixctl_command_reply(conn, NULL); } + +static void +ovn_northd_pause(struct unixctl_conn *conn, int argc OVS_UNUSED, + const char *argv[] OVS_UNUSED, void *pause_) +{ + bool *pause = pause_; + *pause = true; + + unixctl_command_reply(conn, NULL); +} + +static void +ovn_northd_resume(struct unixctl_conn *conn, int argc OVS_UNUSED, + const char *argv[] OVS_UNUSED, void *pause_) +{ + bool *pause = pause_; + *pause = false; + + unixctl_command_reply(conn, NULL); +} + +static void +ovn_northd_is_paused(struct unixctl_conn *conn, int argc OVS_UNUSED, + const char *argv[] OVS_UNUSED, void *paused_) +{ + bool *paused = paused_; + if (*paused) { + unixctl_command_reply(conn, "true"); + } else { + unixctl_command_reply(conn, "false"); + } +} diff --git a/tests/ovn-northd.at b/tests/ovn-northd.at index 62e58fd0e..0dea04edc 100644 --- a/tests/ovn-northd.at +++ b/tests/ovn-northd.at @@ -898,3 +898,41 @@ as northd OVS_APP_EXIT_AND_WAIT([ovn-northd]) AT_CLEANUP + +AT_SETUP([ovn -- ovn-northd pause and resume]) +AT_SKIP_IF([test $HAVE_PYTHON = no]) +ovn_start + +AT_CHECK([test xfalse = x`as northd ovs-appctl -t ovn-northd is-paused`]) + +ovn-nbctl ls-add sw0 + +OVS_WAIT_UNTIL([ + ovn-sbctl lflow-list sw0 + test 0 = $?]) + +ovn-nbctl ls-del sw0 +OVS_WAIT_UNTIL([ + ovn-sbctl lflow-list sw0 + test 1 = $?]) + +# Now pause the ovn-northd +as northd ovs-appctl -t ovn-northd pause +AT_CHECK([test xtrue = x`as northd ovs-appctl -t ovn-northd is-paused`]) + +ovn-nbctl ls-add sw0 + +# There should be no logical flows for sw0 datapath. +OVS_WAIT_UNTIL([ + ovn-sbctl lflow-list sw0 + test 1 = $?]) + +# Now resume ovn-northd +as northd ovs-appctl -t ovn-northd resume +AT_CHECK([test xfalse = x`as northd ovs-appctl -t ovn-northd is-paused`]) + +OVS_WAIT_UNTIL([ + ovn-sbctl lflow-list sw0 + test 0 = $?]) + +AT_CLEANUP