Abstract: Systems and methods for cluster maintenance are presented. In one embodiment a cluster configuration method includes: maintaining configuration information associated with a first node and a second node, including cluster configuration version information; evaluating the first node as a potential configuration update node for the second node, including evaluating an indication of potential partial snapshot update availability based upon the configuration information associated with the first node and configuration information associated with the second node; performing an update type selection, including continued analysis of partial snapshot update availability; and performing an update for the second node in accordance with results of the update type selection.

Abstract: Systems and methods for cluster maintenance are presented. In one embodiment a cluster configuration method includes: maintaining configuration information associated with a first node and a second node, including cluster configuration version information; evaluating the first node as a potential configuration update node for the second node, including evaluating an indication of potential partial snapshot update availability based upon the configuration information associated with the first node and configuration information associated with the second node; performing an update type selection, including continued analysis of partial snapshot update availability; and performing an update for the second node in accordance with results of the update type selection.

Abstract: Each of the prestressing tendons (3, 4, 18) in a pressure tunnel is made up of a bundle of monostrands (21) held together. Each of the monostrands (21) of one of the prestressing tendons is distanced from adjacent monostrands by the introduction of spacing means (22, 22', 22", 22"') at more or less regular intervals along the length of the prestressing tendon. Distributed along the length of and over the circumference of the pressure tunnel are disposed prestressing tendon supports (9) directed essentially towards the center of the pressure tunnel. Several prestressing tendons (3, 4, 18) are attachable to each of the prestressing tendon supports (9) adjacent to or stacked on top of each other. In doing so, each prestressing tendon (3, 4, 18) is kept spaced from adjacent tendons. The prestressing tendon arrangement ensures that after concreting the pressure tunnel, each of the monostrands is completely embedded in concrete.

Abstract: The prestressed concrete lining has several reinforcement elements (32) distributed around the circumference and along the length of the pressure tunnel. There are prestressing elements (38, 39, 40, 41) which encompass at least a part of the circumference of the pressure tunnel. A bottom part (35) is disposed within the pressure tunnel, formed of several elongated anchorage bodies (15) in series. Each of the anchorage bodies (15) has an essentially U-shaped cross section. In each of the arms (2, 3) of the anchorage bodies turned towards the inside of the tunnel there are first means (5) for passing through at least one of each of the prestressing elements (38, 39, 40, 41). An bearing plate (8) is disposed on each of the facing inner surfaces of the arms in the region of each of the first pass-through means (5). Second means (10) for passing through at least one of each of the prestressing elements (38, 39, 40, 41) are foreseen in the base arm of the anchorage body 15.