This is happening at all times on the server. this I what I got when I restarted the server.

17.03 15:01:11 [Server] Server thread/WARN Can't keep up! Did the system time change, or is the server overloaded? Running 4277ms behind, skipping 85 tick(s)
17.03 15:00:55 [Server] Server thread/WARN Can't keep up! Did the system time change, or is the server overloaded? Running 4184ms behind, skipping 83 tick(s)
17.03 15:00:54 [Server] Server thread/WARN Keeping entity Villager that already exists with UUID 60f55762-b732-4c35-8105-9f94f49aaeac
17.03 15:00:54 [Server] Server thread/WARN Keeping entity Villager that already exists with UUID 60f55762-b732-4c35-8105-9f94f49aaeac
17.03 15:00:50 [Server] Startup Done (9.694s)! For help, type "help" or "?"
17.03 15:00:49 [Server] Server thread/INFO Preparing spawn area: 72%
17.03 15:00:49 [Server] Server thread/WARN Keeping entity EntityHorse that already exists with UUID f165834c-7b36-4a04-bf02-343f3ce61bba
17.03 15:00:48 [Server] Server thread/INFO Preparing spawn area: 46%
17.03 15:00:46 [Server] Server thread/WARN Keeping entity Zombie that already exists with UUID fcec1dea-ffeb-4cb6-b185-2b0f6f5e3bbf
17.03 15:00:46 [Server] Server thread/WARN Keeping entity Zombie that already exists with UUID fcec1dea-ffeb-4cb6-b185-2b0f6f5e3bbf
17.03 15:00:46 [Server] Server thread/WARN Keeping entity Zombie that already exists with UUID fcec1dea-ffeb-4cb6-b185-2b0f6f5e3bbf
17.03 15:00:46 [Server] Server thread/WARN Keeping entity Zombie that already exists with UUID fcec1dea-ffeb-4cb6-b185-2b0f6f5e3bbf
17.03 15:00:46 [Server] Server thread/WARN Keeping entity Zombie that already exists with UUID fcec1dea-ffeb-4cb6-b185-2b0f6f5e3bbf
17.03 15:00:46 [Server] Server thread/WARN Keeping entity Zombie that already exists with UUID fcec1dea-ffeb-4cb6-b185-2b0f6f5e3bbf
17.03 15:00:46 [Server] Server thread/WARN Keeping entity Zombie that already exists with UUID fcec1dea-ffeb-4cb6-b185-2b0f6f5e3bbf
17.03 15:00:46 [Server] Server thread/INFO Preparing spawn area: 38%
17.03 15:00:45 [Server] Server thread/INFO Preparing spawn area: 27%
17.03 15:00:45 [Server] Server thread/WARN Keeping entity Chicken that already exists with UUID 9f884d4d-12ec-4521-b4ff-8e116c135575
17.03 15:00:44 [Server] Server thread/WARN Keeping entity Villager that already exists with UUID eb26ab6e-cb30-42f0-94ec-263059434d97
17.03 15:00:44 [Server] Server thread/WARN Keeping entity Villager that already exists with UUID 91289787-5e0b-4b85-ba04-31c906c6ad8a
17.03 15:00:44 [Server] Server thread/WARN Keeping entity Villager that already exists with UUID 91289787-5e0b-4b85-ba04-31c906c6ad8a
17.03 15:00:44 [Server] Server thread/WARN Keeping entity Villager that already exists with UUID 582f295b-fbd1-40f0-8055-3d566c0ebdda
17.03 15:00:44 [Server] Server thread/WARN Keeping entity Villager that already exists with UUID 582f295b-fbd1-40f0-8055-3d566c0ebdda
17.03 15:00:44 [Server] Server thread/INFO Preparing spawn area: 3%
17.03 15:00:43 [Server] Server thread/INFO Preparing spawn area: 0%
17.03 15:00:41 [Server] Server thread/INFO Preparing start region for level 0
17.03 15:00:40 [Server] Server thread/INFO Preparing level "Hadean"
17.03 15:00:40 [Server] Server thread/INFO Using epoll channel type
17.03 15:00:40 [Server] Server thread/INFO Starting Minecraft server on 198.24.168.250:30079
17.03 15:00:39 [Server] Server thread/INFO Generating keypair
17.03 15:00:39 [Server] Server thread/INFO Default game type: SURVIVAL
17.03 15:00:39 [Server] Server thread/INFO Loading properties
17.03 15:00:39 [Server] Server thread/INFO Starting minecraft server version 1.9