NTP should be used on all Caringo Swarm products to avoid side effects from the leap second issue. Use of NTP is and has been strongly recommended for all Caringo Swarm products. Current CSN and Swarm versions have already been patched:
...
Swarm: 7.2.3
For any other Caringo Swarm products, please make sure that NTP has been updated to at least 4.2.6p5. https://rhn.redhat.com/errata/RHBA-2015-0690.html