[pve-devel] [PATCH ha-manager v2 15/26] manager: handle migrations for colocated services

[Daniel Kral]

Make positively colocated services migrate to the same target node as
the manually migrated service and prevent a service to be manually
migrated to a node, which contains negatively colocated services.

The log information here is only redirected to the HA Manager node's
syslog, so user-facing endpoints need to implement this logic as well to
give users adequate feedback about the errors and side-effects.

Signed-off-by: Daniel Kral <d.kral at proxmox.com>
---
changes since v1:
    - NEW!

 src/PVE/HA/Manager.pm          | 44 ++++++++++++++++++++++++++++--
 src/PVE/HA/Rules/Colocation.pm | 50 ++++++++++++++++++++++++++++++++++
 2 files changed, 91 insertions(+), 3 deletions(-)

diff --git a/src/PVE/HA/Manager.pm b/src/PVE/HA/Manager.pm
index a69898b..66e5710 100644
--- a/src/PVE/HA/Manager.pm
+++ b/src/PVE/HA/Manager.pm
@@ -12,7 +12,7 @@ use PVE::HA::NodeStatus;
 use PVE::HA::Rules;
 use PVE::HA::Rules::Location qw(get_location_preference);
 use PVE::HA::Rules::Colocation
-    qw(get_colocation_preference apply_positive_colocation_rules apply_negative_colocation_rules);
+    qw(get_colocated_services get_colocation_preference apply_positive_colocation_rules apply_negative_colocation_rules);
 use PVE::HA::Usage::Basic;
 use PVE::HA::Usage::Static;
 
@@ -412,6 +412,45 @@ sub read_lrm_status {
     return ($results, $modes);
 }
 
+sub execute_migration {
+    my ($self, $cmd, $task, $sid, $target) = @_;
+
+    my ($haenv, $ss) = $self->@{qw(haenv ss)};
+
+    my ($together, $separate) = get_colocated_services($self->{rules}, $sid);
+
+    for my $csid (sort keys %$separate) {
+        next if $ss->{$csid}->{node} && $ss->{$csid}->{node} ne $target;
+        next if $ss->{$csid}->{target} && $ss->{$csid}->{target} ne $target;
+
+        $haenv->log(
+            'err',
+            "crm command '$cmd' error - negatively colocated service '$csid' on '$target'",
+        );
+
+        return; # one negative colocation is enough to not execute migration
+    }
+
+    $haenv->log('info', "got crm command: $cmd");
+    $ss->{$sid}->{cmd} = [$task, $target];
+
+    my $services_to_migrate = [];
+    for my $csid (sort keys %$together) {
+        next if $ss->{$csid}->{node} && $ss->{$csid}->{node} eq $target;
+        next if $ss->{$csid}->{target} && $ss->{$csid}->{target} eq $target;
+
+        push @$services_to_migrate, $csid;
+    }
+
+    for my $csid (@$services_to_migrate) {
+        $haenv->log(
+            'info',
+            "crm command '$cmd' - $task positively colocated service '$csid' to '$target'",
+        );
+        $ss->{$csid}->{cmd} = [$task, $target];
+    }
+}
+
 # read new crm commands and save them into crm master status
 sub update_crm_commands {
     my ($self) = @_;
@@ -435,8 +474,7 @@ sub update_crm_commands {
                             "ignore crm command - service already on target node: $cmd",
                         );
                     } else {
-                        $haenv->log('info', "got crm command: $cmd");
-                        $ss->{$sid}->{cmd} = [$task, $node];
+                        $self->execute_migration($cmd, $task, $sid, $node);
                     }
                 }
             } else {
diff --git a/src/PVE/HA/Rules/Colocation.pm b/src/PVE/HA/Rules/Colocation.pm
index 190478e..45d20d0 100644
--- a/src/PVE/HA/Rules/Colocation.pm
+++ b/src/PVE/HA/Rules/Colocation.pm
@@ -11,6 +11,7 @@ use base qw(Exporter);
 use base qw(PVE::HA::Rules);
 
 our @EXPORT_OK = qw(
+    get_colocated_services
     get_colocation_preference
     apply_positive_colocation_rules
     apply_negative_colocation_rules
@@ -295,6 +296,55 @@ sub plugin_canonicalize {
 
 =cut
 
+=head3 get_colocated_services($rules, $sid)
+
+Returns a list of two hash sets, where the first hash set contains the
+positively colocated services for C<$sid>, while the second hash set contains
+the negatively colocated services for C<$sid> according to the colocation rules
+in C<$rules>.
+
+For example, if a service is in a negative colocation with C<'vm:101'> and in a
+positive colocation with C<'ct:200'> and C<'ct:201'>, the returned value will be:
+
+    {
+        together => {
+            'vm:101' => 1
+        },
+        separate => {
+            'ct:200' => 1,
+            'ct:201' => 1
+        }
+    }
+
+=cut
+
+sub get_colocated_services : prototype($$) {
+    my ($rules, $sid) = @_;
+
+    my $together = {};
+    my $separate = {};
+
+    PVE::HA::Rules::foreach_rule(
+        $rules,
+        sub {
+            my ($rule, $ruleid) = @_;
+
+            my $affinity_set = $rule->{affinity} eq 'together' ? $together : $separate;
+
+            for my $csid (sort keys %{ $rule->{services} }) {
+                $affinity_set->{$csid} = 1 if $csid ne $sid;
+            }
+        },
+        {
+            sid => $sid,
+            type => 'colocation',
+            state => 'enabled',
+        },
+    );
+
+    return ($together, $separate);
+}
+
 =head3 get_colocation_preference($rules, $sid, $online_node_usage)
 
 Returns a list of two hashes, where the first describes the positive colocation
-- 
2.39.5