??????no response for get children

[happen]

  Hi,


      I found a strange thing in zk 3.5.6 that sometimes 
observers ignored one get children req (local session). thougth other watch 
events could still be sent to the involved c++  client. Then the involved 
client  waited the get children reponse for totally session timeout time and no 
ping could be sent to observer until the session expired.  The client said 
"invalid zhandle state" after session expired.
     


     The issue's frequency situation: 
         
       A)  1 to 5 get children requests are 
ignored per minute  when:  6000 client is connected to one observer, 
zk_packets_sent 2M/min, zk_packets_received 1M/min;
       B) and less get children requests are ignored 
when lower zk_packets_sent and zk_packets_received.



     


     I caught packets for the journey, no one reponses for the ignored get 
children req when it occurred.


    Why  sometimes get children req.s were ignored ?  


    Is it possible a bug in zk3.5.6 ?





------------------ ???????? ------------------
??????:                                                                         
                                               "happen"                         
                                                           
<370119...@qq.com&gt;;
????????:&nbsp;2020??8??16??(??????) ????10:12
??????:&nbsp;"dev"<dev@zookeeper.apache.org&gt;;

????:&nbsp;no response for get children



&nbsp; Hi, 


&nbsp; &nbsp; &nbsp; I found a strange thing in zk 3.5.6 that sometimes 
observers ignored one get children req (local session). thougth watch events 
still was sent to the c++  client. Then the client  waited the get children 
reponse for totally session timeout time and no ping could be sent to server 
until session expired.  The client said "invalid zk handle" after session 
expired.
     


     The issue's frequency situation: 
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;
&nbsp; &nbsp; &nbsp; &nbsp;A)&nbsp; 1 to 5 get children requests are ignored 
per minute  when:  6000 client is connected to one observer, zk_packets_sent 
2M/min, zk_packets_received 1M/min;
&nbsp; &nbsp; &nbsp; &nbsp;B) and less get children requests are ignored when 
lower zk_packets_sent and zk_packets_received.



     


     I caught packets for the journey, no one reponses for the ignored get 
children req when it occurred.


    Why  sometimes get children req.s were ignored ?  


    Is it possible a bug in zk3.5.6 ?