X-Git-Url: https://git.arvados.org/arvados.git/blobdiff_plain/050be6a5be43ab503820955dbca2751ca368063c..3294cfcee6d9316df0d0fae9848118501f57d908:/services/api/app/models/node.rb

diff --git a/services/api/app/models/node.rb b/services/api/app/models/node.rb
index f04fa70c1b..3d8b91b4b6 100644
--- a/services/api/app/models/node.rb
+++ b/services/api/app/models/node.rb
@@ -1,3 +1,7 @@
+# Copyright (C) The Arvados Authors. All rights reserved.
+#
+# SPDX-License-Identifier: AGPL-3.0
+
 require 'tempfile'
 
 class Node < ArvadosModel
@@ -102,27 +106,7 @@ class Node < ArvadosModel
       end
     end
 
-    # Assign slot_number
-    if self.slot_number.nil?
-      while true
-        n = self.class.available_slot_number
-        if n.nil?
-          raise "No available node slots"
-        end
-        self.slot_number = n
-        begin
-          self.save!
-          break
-        rescue ActiveRecord::RecordNotUnique
-          # try again
-        end
-      end
-    end
-
-    # Assign hostname
-    if self.hostname.nil? and Rails.configuration.assign_node_hostname
-      self.hostname = self.class.hostname_for_slot(self.slot_number)
-    end
+    assign_slot
 
     # Record other basic stats
     ['total_cpu_cores', 'total_ram_mb', 'total_scratch_mb'].each do |key|
@@ -136,9 +120,34 @@ class Node < ArvadosModel
     save!
   end
 
+  def assign_slot
+    return if self.slot_number.andand > 0
+    while true
+      self.slot_number = self.class.available_slot_number
+      if self.slot_number.nil?
+        raise "No available node slots"
+      end
+      begin
+        save!
+        return assign_hostname
+      rescue ActiveRecord::RecordNotUnique
+        # try again
+      end
+    end
+  end
+
   protected
 
+  def assign_hostname
+    if self.hostname.nil? and Rails.configuration.assign_node_hostname
+      self.hostname = self.class.hostname_for_slot(self.slot_number)
+    end
+  end
+
   def self.available_slot_number
+    # Join the sequence 1..max with the nodes table. Return the first
+    # (i.e., smallest) value that doesn't match the slot_number of any
+    # existing node.
     connection.exec_query('SELECT n FROM generate_series(1, $1) AS slot(n)
                           LEFT JOIN nodes ON n=slot_number
                           WHERE slot_number IS NULL
@@ -146,8 +155,7 @@ class Node < ArvadosModel
                           # query label:
                           'Node.available_slot_number',
                           # [col_id, val] for $1 vars:
-                          [['max_compute_nodes',
-                            Rails.configuration.max_compute_nodes]],
+                          [[nil, Rails.configuration.max_compute_nodes]],
                          ).rows.first.andand.first
   end