replace safe_set with set

prometheus.lua

@@ -424,16 +424,16 @@ end
 --   value: numeric value to increment by. Can be negative.
 --   label_values: a list of label values, in the same order as label keys.
 local function inc_gauge(self, value, label_values)
-  local k, err, _
+  local k, err, _, forcible
   k, err = lookup_or_create(self, label_values)
   if err then
     self._log_error(err)
     return
   end
 
-  _, err, _ = self._dict:incr(k, value, 0)
-  if err then
-    self._log_error_kv(k, value, err)
+  _, err, forcible = self._dict:incr(k, value, 0)
+  if err or forcible then
+    self._log_error_kv(k, value, err or "lru eviction")
   end
 end
 
@@ -521,15 +521,15 @@ local function set(self, value, label_values)
     return
   end
 
-  local k, _, err
+  local k, _, err, forcible
   k, err = lookup_or_create(self, label_values)
   if err then
     self._log_error(err)
     return
   end
-  _, err = self._dict:safe_set(k, value)
-  if err then
-    self._log_error_kv(k, value, err)
+  _, err, forcible = self._dict:set(k, value)
+  if err or forcible then
+    self._log_error_kv(k, value, err or "lru eviction")
   end
 end
 
@@ -632,7 +632,7 @@ local function reset(self)
       end
       if remove then
         self._key_index:remove(key)
-        local _, err = self._dict:safe_set(key, nil)
+        local _, err = self._dict:set(key, nil)
         if err then
           self._log_error("Error resetting '", key, "': ", err)
         end

prometheus_keys.lua

@@ -85,7 +85,11 @@ function KeyIndex:add(key_or_keys)
         break
       end
       N = N+1
-      local ok, err = self.dict:safe_add(self.key_prefix .. N, key)
+      local ok, err, forcible = self.dict:add(self.key_prefix .. N, key)
+      if forcible then
+          ngx.log(ngx.ERR, "key index: add key: shdict lru eviction: idx=",
+                  self.key_prefix .. N, ", key=", key)
+      end
       if ok then
         self.dict:incr(self.key_count, 1, 0)
         self.keys[N] = key
@@ -107,7 +111,7 @@ function KeyIndex:remove(key)
   if i then
     self.index[key] = nil
     self.keys[i] = nil
-    self.dict:safe_set(self.key_prefix .. i, nil)
+    self.dict:set(self.key_prefix .. i, nil)
     -- increment delete_count to signalize other workers that they should do a full sync
     self.dict:incr(self.delete_count, 1, 0)
     self.deleted = self.deleted + 1

prometheus_resty_counter.lua

@@ -31,10 +31,13 @@ local timer_started = {}
 local id
 
 local function sync(_, self)
-  local err, _
+  local err, _, forcible
   local ok = true
   for k, v in pairs(self.increments) do
-    _, err, _ = self.dict:incr(k, v, 0)
+    _, err, forcible = self.dict:incr(k, v, 0)
+    if forcible then
+      ngx.log(ngx.WARN, "increasing counter in shdict: lru eviction: key=", k)
+    end
     if err then
       ngx.log(ngx.WARN, "error increasing counter in shdict key: ", k, ", err: ", err)
       ok = false

prometheus_test.lua

@@ -14,17 +14,11 @@ function SimpleDict:safe_set(k, v)
   self:set(k, v)
   return true, nil  -- ok, err
 end
-function SimpleDict:safe_add(k, v)
-  if k == "willnotfit" or v == "willnotfit" then
-    return nil, "no memory"
-  end
+function SimpleDict:add(k, v)
   self:set(k, v)
   return true, nil  -- ok, err
 end
 function SimpleDict:incr(k, v, init)
-  if k:find("willnotfit") then
-    return nil, "no memory"
-  end
   if not self.dict[k] then self.dict[k] = init end
   self.dict[k] = self.dict[k] + (v or 1)
   return self.dict[k], nil  -- newval, err
@@ -168,17 +162,6 @@ function TestPrometheus.testErrorUnknownDict()
   luaunit.assertEquals(pok, false)
   luaunit.assertStrContains(perr, "does not seem to exist")
 end
-function TestPrometheus:testErrorNoMemory()
-  local gauge3 = self.p:gauge("willnotfit")
-  self.counter1:inc(5)
-  gauge3:inc(1)
-
-  self.p._counter:sync()
-  luaunit.assertEquals(self.dict:get("metric1"), 5)
-  luaunit.assertEquals(self.dict:get("nginx_metric_errors_total"), 1)
-  luaunit.assertEquals(self.dict:get("willnotfit"), nil)
-  luaunit.assertEquals(#ngx.logs, 1)
-end
 function TestPrometheus:testErrorInvalidMetricName()
   self.p:histogram("name with a space", "Histogram")
   self.p:gauge("nonprintable\004characters", "Gauge")
@@ -703,11 +686,6 @@ function TestKeyIndex:testAdd()
   self.key_index:add("single")
   luaunit.assertEquals(ngx.logs, nil)
   luaunit.assertEquals(self.dict:get("_prefix_key_count"), 3)
-
-  -- error should be returned when memory is full
-  local err = self.key_index:add("willnotfit")
-  luaunit.assertEquals(err, "Unexpected error adding a key: no memory")
-  luaunit.assertEquals(self.dict:get("_prefix_key_count"), 3)
 end
 function TestKeyIndex:testRemove()
   self.key_index:add({"key1", "key2", "key3"})