chore(rpc): add debugging logs

kong/clustering/rpc/manager.lua

@@ -18,6 +18,7 @@ local cjson = require("cjson.safe")
 
 local ngx_var = ngx.var
 local ngx_ERR = ngx.ERR
+local ngx_DEBUG = ngx.DEBUG
 local ngx_log = ngx.log
 local ngx_exit = ngx.exit
 local ngx_time = ngx.time
@@ -172,8 +173,17 @@ function _M:call(node_id, method, ...)
 
   local params = {...}
 
+  ngx_log(ngx_DEBUG,
+    "[rpc] calling ", method,
+    "(node_id: ", node_id, ")",
+    " via ", res == "local" and "local" or "concentrator"
+  )
+
   if res == "local" then
     res, err = self:_local_call(node_id, method, params)
+
+    ngx_log(ngx_DEBUG, "[rpc] ", method, err and " failed" or " succeeded")
+
     if not res then
       return nil, err
     end
@@ -188,6 +198,9 @@ function _M:call(node_id, method, ...)
   assert(fut:start())
 
   local ok, err = fut:wait(5)
+
+  ngx_log(ngx_DEBUG, "[rpc] ", method, err and " failed" or " succeeded")
+
   if err then
     return nil, err
   end

kong/clustering/rpc/socket.lua

@@ -148,6 +148,7 @@ function _M:start()
       if payload.method then
         -- invoke
 
+        ngx_log(ngx_DEBUG, "[rpc] got RPC call: ", payload.method, " (id: ", payload.id, ")")
         local dispatch_cb = self.manager.callbacks.callbacks[payload.method]
         if not dispatch_cb then
           local res, err = self.outgoing:push(new_error(payload.id, jsonrpc.METHOD_NOT_FOUND))

kong/clustering/services/sync/hooks.lua

@@ -59,6 +59,8 @@ function _M:notify_all_nodes()
     return
   end
 
+  ngx_log(ngx_DEBUG, "[rpc:sync] notifying all nodes of new version: ", latest_version)
+
   local msg = { default = { new_version = latest_version, }, }
 
   for _, node in ipairs(get_all_nodes_with_sync_cap()) do
@@ -112,6 +114,7 @@ end
 -- only control plane has these delta operations
 function _M:register_dao_hooks()
   local function is_db_export(name)
+    ngx_log(ngx_DEBUG, "[rpc:sync] name: ", name, " db_export: ", kong.db[name].schema.db_export)
     local db_export = kong.db[name].schema.db_export
     return db_export == nil or db_export == true
   end
@@ -131,6 +134,7 @@ function _M:register_dao_hooks()
       return
     end
 
+    ngx_log(ngx_DEBUG, "[rpc:sync] failed. Canceling ", name)
     local res, err = self.strategy:cancel_txn()
     if not res then
       ngx_log(ngx_ERR, "unable to cancel cancel_txn: ", tostring(err))
@@ -142,6 +146,7 @@ function _M:register_dao_hooks()
       return entity
     end
 
+    ngx_log(ngx_DEBUG, "[rpc:sync] new delta due to writing ", name)
     return self:entity_delta_writer(entity, name, options, ws_id)
   end
 
@@ -150,7 +155,8 @@ function _M:register_dao_hooks()
       return entity
     end
 
-    -- set lmdb value to ngx_null then return entity
+    ngx_log(ngx_DEBUG, "[rpc:sync] new delta due to deleting ", name)
+    -- set lmdb value to ngx_null then return row
     return self:entity_delta_writer(entity, name, options, ws_id, true)
   end