c++cmemcachedlibmemcache

libmemcached : SERVER HAS FAILED AND DISABLED UNTIL TIMED RETRY

I am using libmemcached C API for interacting with memcached. Occasionally memcached_set fails with SERVER HAS FAILED AND DISABLED UNTIL TIMED RETRY. What can be a general approach to handle this issue.

This error only occurs on production servers, and it is not producible in development environment.

Following is the pseudo code snippet, cannot post entire code.

bool set_keys(std::string const & query)
{
  // create a DB connection
  // execute query
  // consider result of query is as following
  std::vector<std::tuple<std::string,std::string>>result_set;
  memcached_return rc;
  for(auto const & item :  result_set )
  {
      rc= memcached_set(memc, std::get<0>(item).c_str(), std::get<0>(item).size(),  std::get<1>(item).c_str(),  std::get<1>(item).size(), (time_t)0, (uint32_t)0);

       if (rc != MEMCACHED_SUCCESS)
            fprintf(stderr,"Couldn't store key: %s\n",memcached_strerror(memc, rc));
   }
}

One thing I noticed that memcached_server_list_append is not used anywhere in code after creations of memcached connection, can this cause issues?

Solution

  • Possible the server is overloaded. Check the loading of memcached by top.

    Check the key names when set for valid values.

    Try to set Memcached::OPT_BINARY_PROTOCOL, to enable binary data.