how hiredis clients know server down ?

[pad...@gmail.com]

Hi.

I need to know a way for hiredis clients to detect server down during command session for clients' safety.

I inserted sleep(30) in the middle of command session of hiredis/example.c. While the client is sleeping,

I stopped the redis-server to which the client has connection. After the client woke up, it crashes. Here's

output to stdout.

  $ ./hiredis-example

  PING: PONG

  SET: OK

  SET (binary API): OK

  GET foo: hello world

  INCR counter: 5

  INCR counter: 6

  Segmentation fault (core dumped)

Segmentation fault cannot be acceptable for a server process. It may be better to interleave connect and

disconnect for every redis command session but this is not perfect.

Let me know a programming pattern or such example of a redis client (by hiredis) to keep working (not to die)

by redis-server down (or error) during client's command session.

Thanks in advance.

[paulinohuerta]

Hi,

The err field inside the context will be non-zero, when a  function call is not successful.

   

 //example:

 //if exists the definition:    redisContext *c;

 //and it allocate a redis context

 //then,

 for(j=1;j<=10;j++) {

       reply = redisCommand(c,"PING");

       if(c->err == 0){

          printf("PING: %s\n", reply->str);

          freeReplyObject(reply);

       }

       else { printf("Error: %s\n",c->errstr);}

       sleep(4);

 }

Regards,

--Paulino

[pad...@gmail.com]

Oh. It is so simple. Thank you.

2014年12月7日日曜日 23時19分12秒 UTC+9 paulinohuerta: