write trainer_desc file (#44702)

* back fl

* delete ssl cert

* .

* make warning

* .

* unittest paral degree

* solve unittest

* heter & multi cloud commm ready

* .

* .

* fl-ps v1.0

* .

* support N + N mode

* .

* .

* .

* .

* delete print

* .

* .

* .

* .

* fix bug

* .

* .

* fl-ps with coordinator ready

* merge dev

* update message parse only

* update fl client scheduler

* fix bug

* update multithreads sync

* fix ci errors

* update role_maker.py

* update role_maker.py

* fix ci error: windows py import error

* fix ci error: windows py import error

* fix windows ci pylib import error

* add dump fields & params

* try to fix windows import fleet error

* fix ps FLAGS error

* fix logging risk

* fix logging possible risk

* write trainer_desc file

python/paddle/fluid/executor.py

@@ -1689,8 +1689,8 @@ class Executor(object):
         return res
 
     def _dump_debug_info(self, program=None, trainer=None):
-        print("program_id: {}, trainer_desc:\n {}".format(
-            id(program), str(trainer)))
+        with open(str(id(program)) + "_train_desc.prototxt", "w") as fout:
+            fout.write(str(trainer))
         if program._fleet_opt and "fleet_desc" in program._fleet_opt:
             with open("fleet_desc.prototxt", "w") as fout:
                 fout.write(str(program._fleet_opt["fleet_desc"]))