diff --git a/lib/vmpooler/providers/gce.rb b/lib/vmpooler/providers/gce.rb
index e7d838d..747872e 100644
--- a/lib/vmpooler/providers/gce.rb
+++ b/lib/vmpooler/providers/gce.rb
@@ -460,15 +460,17 @@ module Vmpooler
           true
         end
 
-        def vm_ready?(pool_name, vm_name)
+        def vm_ready?(pool_name, vm_name, redis)
           debug_logger('vm_ready?')
           begin
             # TODO: we could use a healthcheck resource attached to instance
             domain = domain(pool_name)
             open_socket(vm_name, domain)
-          rescue StandardError => _e
+          rescue StandardError => e
+            redis.hset("vmpooler__vm__#{vm_name}", 'open_socket_error', e.to_s)
             return false
           end
+          redis.hdel("vmpooler__vm__#{vm_name}", 'open_socket_error')
           true
         end
 
diff --git a/spec/unit/providers/gce_spec.rb b/spec/unit/providers/gce_spec.rb
index 614a23b..1e219b9 100644
--- a/spec/unit/providers/gce_spec.rb
+++ b/spec/unit/providers/gce_spec.rb
@@ -361,7 +361,9 @@ EOT
       end
 
       it 'should return true' do
-        expect(subject.vm_ready?(poolname, vmname)).to be true
+        redis_connection_pool.with_metrics do |redis|
+          expect(subject.vm_ready?(poolname, vmname, redis)).to be true
+        end
       end
     end
 
@@ -371,7 +373,9 @@ EOT
       end
 
       it 'should return false' do
-        expect(subject.vm_ready?(poolname, vmname)).to be false
+        redis_connection_pool.with_metrics do |redis|
+          expect(subject.vm_ready?(poolname, vmname, redis)).to be false
+        end
       end
     end
   end