A cooling system for a rack of servers (105a, 105b, ···, 105n), comprising: a plurality of cooling circuits (120a, 120b, ···, 120n), each cooling circuit (120a, 120b,···, 120n) coupled to a server (105a, 105b, ···, 105n) of the rack and comprising: a plurality of cooling modules (230, 2301, 2302, 2303) arranged in parallel, each cooling module (230, 2301, 2302, 2303) including a cold plate having a cooling conduit (234, 2341, 2342, 2343) passing therethrough, and a pump (236, 2361, 2362, 2363) fluidly coupled to the cooling conduit (234, 2341, 2342, 2343); a first cooling distribution manifold fluidly connected to the cooling circuit (120a, 120b, ···, 120n) of each of the plurality of servers (105a, 105b, ···, 105n) through an inlet pipe (124a, 124b, ···, 124n); and a second cooling distribution manifold fluidly connected to the cooling circuit (120a, 120b, ···, 120n) of each of the plurality of servers (105a, 105b, ···, 105n) through an outlet pipe (128a, 128b, ···, 128n); wherein the cooling system is characterized in that any two adjacent cooling modules (230 1, 230 2,230 3) are interconnected by a valve (340, 340 1, 340 2) having four ports (342, 344, 346, 348, 342 1, 344 1, 346 1, 348 1, 342 2, 344 2, 346 2, 348 2), the valve (340, 340 1, 340 2) is one of a four-pass actuated ball valve and a four-pass valve formed by three two-pass solenoid valves, two of the ports (342, 344, 346, 348, 342 1, 344 1, 346 1, 348 1, 342 2, 344 2, 346 2, 348 2) are fluidly coupled to an outlet tube (360 1, 360 2, 360 3) of each cooling module (230 1, 230 2, 230 3), and another two of the ports (342, 344, 346, 348, 342 1, 344 1, 346 1, 348 1, 342 2, 344 2, 346 2, 348 2) are fluidly coupled to an inlet tube (350 1, 350 2, 350 3) of each cooling module (230 1, 230 2, 230 3). a plurality of cooling circuits (120a, 120b, ···, 120n), each cooling circuit (120a, 120b,···, 120n) coupled to a server (105a, 105b, ···, 105n) of the rack and comprising: a plurality of cooling modules (230, 2301, 2302, 2303) arranged in parallel, each cooling module (230, 2301, 2302, 2303) including a cold plate having a cooling conduit (234, 2341, 2342, 2343) passing therethrough, and a pump (236, 2361, 2362, 2363) fluidly coupled to the cooling conduit (234, 2341, 2342, 2343); a first cooling distribution manifold fluidly connected to the cooling circuit (120a, 120b, ···, 120n) of each of the plurality of servers (105a, 105b, ···, 105n) through an inlet pipe (124a, 124b, ···, 124n); and a second cooling distribution manifold fluidly connected to the cooling circuit (120a, 120b, ···, 120n) of each of the plurality of servers (105a, 105b, ···, 105n) through an outlet pipe (128a, 128b, ···, 128n); wherein the cooling system is characterized in that any two adjacent cooling modules (230 1, 230 2,230 3) are interconnected by a valve (340, 340 1, 340 2) having four ports (342, 344, 346, 348, 342 1, 344 1, 346 1, 348 1, 342 2, 344 2, 346 2, 348 2), the valve (340, 340 1, 340 2) is one of a four-pass actuated ball valve and a four-pass valve formed by three two-pass solenoid valves, two of the ports (342, 344, 346, 348, 342 1, 344 1, 346 1, 348 1, 342 2, 344 2, 346 2, 348 2) are fluidly coupled to an outlet tube (360 1, 360 2, 360 3) of each cooling module (230 1, 230 2, 230 3), and another two of the ports (342, 344, 346, 348, 342 1, 344 1, 346 1, 348 1, 342 2, 344 2, 346 2, 348 2) are fluidly coupled to an inlet tube (350 1, 350 2, 350 3) of each cooling module (230 1, 230 2, 230 3).