How to connect to zookeeper server from different machine? - c

Question

My code, which is written in C for the C Client binding for zookeeper, runs perfectly on my local computer using the same ip (not localhost:2181). However, compiling and executing my code on another computer yields with a connection loss error. I was not able to connect to my zookeeper server by using my public IP(I got my publicIP by looking up whatsmyip on google). I did an ifconfig on my terminal to get the 10.111.129.199. I am assuming this is a private IP as it starts with 10. The machine I have ssh'd to is running SolarisOS. This caused me to change a single function in zookeeper source code from synch_fetch_and_add (I think) to atomic_add because sync_fetch... is not supported by SolarisOS. According to ZooKeeper documentation, SolarisOS is not currently supported by Zookeeper. I am able to compile Zookeeper perfectly fine, and am told someone else in my company had implemented Zookeeper beforehand on our systems.
My program is trying to create a single node on the zookeeper server. My code looks like this:
int main(int argc, char *argv[]){
//zh is a global zookeeper_handle for now.
zh = zookeeper_init(host_port, my_watcher_func, 20000, 0, NULL, 0);
if(zh == NULL){
fprintf(stderr, "Error connecting to ZooKeeper Server!! \n");
exit(EXIT_FAILURE);
return 0;
}
int retval = create("/TFS/pool" , "1");
printf("return value of create = %d\n", retval);
}
int create(char* path, char* data){
int value_length= -1;
if(data != NULL){
value_length = (int) strlen(data);
}
printf("creating node at path: %s with data %s\n", path, data);
int retval = zoo_create( zh, path, data, value_length,
&ZOO_OPEN_ACL_UNSAFE, 0, 0, 0);
return retval;
}
/*empty watcher function*/
//I have no idea why this is needed.
void my_watcher_func(zhandle_t *zzh, int type, int state,
const char *path, void *watcherCtx) {}
Both systems are running GCC compiler. The problem, I think, isn't in the code as it runs fine locally, but the connection issue I am facing.
I would assume that zh would return 0 if the connection to the zookeeper was a failure from the zookeeper_init() function. This however does not happen and continues to the create().
creating node at path: /TFS/pool with data abc
2018-07-16
10:30:44,232:16332(0x2):ZOO_ERROR#handle_socket_error_msg#1670: Socket
[10.111.129.190:2181] zk retcode=-4, errno=0(Error 0): connect() call
failed
return value of create = -4
When I telnet to the ip:port it will connect. I also know that zookeeper detects my connection during telnet because I am running it in the foreground. The following is the output of zkServer.sh running in foreground when I connect via telnet 10.111.129.190 2181
2018-07-16 11:04:03,807 [myid:] - INFO
[NIOServerCxn.Factory:0.0.0.0/0.0.0.0:2181:NIOServerCnxnFactory#215] -
Accepted socket connection from /10.7.1.70:61479
The expected output should have been:
creating node at path: /TFS/pool with data 1
2018-07-16 12:14:37,078:3180(0x70000c98c000):ZOO_INFO#check_events#1764: initiated connection to server [10.111.129.190:10101]
2018-07-16 12:14:37,107:3180(0x70000c98c000):ZOO_INFO#check_events#1811: session establishment complete on server [10.111.129.190:10101], sessionId=0x10000590d2b0000, negotiated timeout=20000
return value of create = 0
This output has always confused me as zookeeper connection is established after the zookeeper_handle is initiated. It is established upon zoo_create() instead of zookeeper_init. Doesn't effect anything, but just an interesting time to establish a connection.
I understand that retcode=-4 means CONNECTIONLOSS, but it's not even able to establish a connection with the server. If there is anyway I could fix this please do tell!.