1. A method for detecting a high pressure condition within a high voltage vacuum device, comprising:
sensing a position of a movable structure, said position of said movable structure being responsive to a pressure within said high voltage vacuum device, wherein sensing said position of said movable structure further comprises
transmitting an optical beam to a first position on a hemispherically shaped reflecting surface,
reflecting a portion of said optical beam from said first position to a second position on said hemispherically shaped reflecting surface, and
blocking said portion of said optical beam being reflected from said first position to said second position with a portion of said movable structure at said high pressure condition; and,
providing an output responsive to blocking said portion of said optical beam.
2. The method as recited in claim 1, wherein said high voltage is an AC voltage greater than 1000 volts.
3. The method as recited in claim 1, wherein said high voltage vacuum device is a high voltage vacuum switch.
4. The method as recited in claim 1, wherein said high voltage vacuum device is a high voltage vacuum capacitor.
5. The method as recited in claim 1, further comprising:
providing a gas container, having a first end plate, a second end plate, and a bellows wall section coupling said first end plate to said second end plate, such that said first end plate, said second end plate, and said bellows wall structure forming a gas tight enclosure, wherein said second end plate moves relative to said first end plate depending on a pressure within said gas container; and,
providing a rigid fluid conduit, attached between said first end plate and said high voltage vacuum device, such that said pressure within said high voltage vacuum device is approximately equal to said pressure with said gas container, said first end plate fixed relative to said high voltage vacuum device, wherein said movable structure is attached to said second end plate.
6. A method for detecting loss of vacuum in a vacuum pressure-type electrical device comprising a bottle for defining a vacuum pressure condition at the interior of the bottle, and electrical charge members in the bottle mounted for relative movement between a first position in which the electrical charge members are positioned closely adjacent and a second position in which the electrical charge members are spaced apart, with the vacuum in the bottle preventing electrical arcing between the electrical charge members when they are moved between their first and second positions at voltage potentials in excess of 1000 volts, the method comprising:
operatively associating a movable structure having first and second sides with the bottle;
exposing the first side of the movable structure to the vacuum pressure condition in the bottle;
exposing the second side of the movable structure to a second pressure condition exterior of the bottle, with the movable structure moving in response to the loss of the vacuum pressure condition in the bottle;
monitoring movement of the movable structure to detect the loss of the vacuum pressure condition in the bottle when the electrical charge members are in either their first or second positions, wherein monitoring the movement of said movable structure further comprises
transmitting an optical beam to a first position on a hemispherically shaped reflecting surface,
reflecting a portion of said optical beam from said first position to a second position on said hemispherically shaped reflecting surface, and
blocking said portion of said optical beam being reflected from said first position to said second position with a portion of said movable structure at said loss of the vacuum pressure condition; and,
providing an output responsive to blocking said portion of said optical beam.
7. The method as recited in claim 6, wherein the output is generated when there is a partial loss of the vacuum pressure in the bottle.
8. The method as recited in claim 6, wherein the output is generated only when there is a full loss of the vacuum pressure in the bottle.
9. An apparatus for detecting a high pressure condition within a high voltage vacuum device, comprising:
a first optical cable, positioned to transmit an optical beam to a first location on a hemispherically shaped reflective surface;
a second optical cable, positioned to receive at least a portion of said optical beam transmitted from said first optical cable, reflected from a second location on said hemispherically shaped reflective surface; and,
a movable structure having a position responsive to a pressure within said high voltage vacuum device, said movable structure extending through an aperture in said hemispherically shaped reflective surface, said aperture being located between said first location and said second location, said movable structure operative to block a least a portion of said optical beam reflected from said first location to said second location at said high pressure condition within said high voltage vacuum device.
10. The apparatus as recited in claim 9 wherein said high voltage vacuum device is a high voltage vacuum switch.
11. The apparatus as recited in claim 9 wherein said high voltage vacuum device is a high voltage vacuum capacitor.
12. The apparatus as recited in claim 9, further comprising:
a gas container, having a first end plate, a second end plate, and a bellows wall section coupling said first end plate to said second end plate, such that said first end plate, said second end plate, and said bellows wall structure form a gas tight enclosure, wherein said second end plate moves relative to said first end plate depending on a pressure within said gas container;
a rigid fluid conduit, attached between said first end plate and said high voltage vacuum device, such that said pressure within said high voltage vacuum device is approximately equal to said pressure with said gas container, said first end plate fixed relative to said high voltage vacuum device; and,
said movable structure attached to said second end plate.
13. The apparatus as recited in claim 9, wherein said first location and said second location are positioned approximately on a circle inscribed on said hemispherically shaped reflective surface, said circle being defined by an intersection of a planar surface and said hemispherically shaped reflective surface, wherein said planar surface is perpendicular to an axis of symmetry of said hemispherically shaped reflective surface, and a radius of said circle is equal to a radius of said hemispherically shaped reflective surface multiplied by one half the square root of 2.
14. The apparatus as recited in claim 13, wherein said optical beam is focused by reflection from said hemispherically shaped reflective surface, prior to reception by said second optical cable.
15. A vacuum bottle-type electrical device with a vacuum pressure loss detection feature comprising:
a bottle defining a vacuum pressure condition at the interior of the bottle;
electrical charge members in the bottle mounted for relative movement between a first position in which the electrical charge members are positioned closely adjacent and an second position in which the electrical charge members are spaced apart from each other, with the vacuum pressure condition in the bottle preventing electrical arcing between the electrical charge members when they are moved between their first and second positions at voltage potentials in excess of 1000V;
a first optical cable, positioned to transmit an optical beam to a first location on a hemispherically shaped reflective surface;
a second optical cable, positioned to receive at least a portion of said optical beam transmitted from said first optical cable, reflected from a second location on said hemispherically shaped reflective surface; and,
a movable structure associated with the bottle having first and second sides, with the movable structure being exposed to the vacuum pressure condition in the bottle at the first side of the movable structure and to a second pressure condition exterior to the bottle at the second side of the movable structure, with the movable structure moving in response to the loss of the vacuum pressure condition in the bottle, a portion of said movable structure extending through an aperture in said hemispherically shaped reflective surface, said aperture being located between said first location and said second location, said portion of said movable structure operative to block a least a portion of said optical beam reflected from said first location to said second location in response to a loss of vacuum pressure condition in the bottle when the electrical charge members are in either their first or second positions.
16. The device as recited in claim 15 wherein the movable structure is a bellows device mounted for movement relative to the bottle in response to the loss of the vacuum condition in the bottle.
17. The device as recited in claim 16 wherein said bellows device is an externally located bellows pressure detection device.
18. The device as recited in claim 16 wherein said bellows device is an internally located bellows pressure detection device.
19. The device as recited in claim 15 wherein the movable structure is a cylinder actuated pressure detection device.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A network of replicated servers providing a service, comprising:
a plurality of server replicas;
a leader elected from among the plurality of server replicas in accordance with a leader election protocol for coordinating ordering of operations among the plurality of server replicas, the remainder of the plurality of server replicas being non-leaders; and
a view change protocol executed by the plurality of server replicas after the election of the leader, each iteration of the view change protocol corresponding to a unique view number,
wherein the view change protocol:
directs each server replica to broadcast its own state and to cooperate with the other server replicas to determine when a sufficient number of server replicas have received states that were broadcasted by a sufficiently large subset of the plurality of server replicas;
directs each non-leader to inform the leader when it is determined that the sufficient number of server replicas have received states that were broadcasted by the sufficiently large subset of the plurality of server replicas;
directs the leader to select an official state from among the states broadcast by the server replicas and broadcast the selection of the official state to the non-leaders;
directs each server replica to agree on the official state selected by the leader;
directs each server replica to cooperate with the other server replicas to order operations not ordered as part of the official state, said cooperation including the exchange of information associated with particular view numbers, wherein said information is prioritized in accordance with said view numbers; and
directs the non-leaders to monitor a length of time between when the non-leader informs the leader that the sufficient number of server replicas have received states that were broadcasted by the sufficiently large subset of the plurality of server replicas and when knowledge of the official state has been received by the non-leader, and to execute the leader election protocol to elect a new leader when it is determined that the monitored length of time is greater than a threshold value that is dependent upon current network conditions.
2. The network of replicated servers of claim 1, wherein the operations whose order is coordinated by the leader include client queries or requests to be processed by the server replicas.
3. The network of replicated servers of claim 1, wherein the state of each of the server replicas is dependent upon what operations were executed by the respective server replica or in what order those operations were executed in.
4. The network of replicated servers of claim 1, wherein the server replicas execute a checkpoint protocol for enabling the server replicas to generate provably-correct checkpoints of their state and then discard messages used to order operations reflected within the state.
5. The network of replicated servers of claim 4, wherein the states broadcast by the server replicas include a most recently-acquired checkpoint and the server replicas determine that they have received the sufficient number of states that were broadcast by the sufficiently large subset of the plurality of server replicas when they have received matching states from a set of 2f+1 server replicas.
6. The network of replicated servers of claim 1, wherein the leader broadcasts the selection of the official state to the non-leaders without broadcasting the official state itself.
7. The network of replicated servers of claim 1, wherein prioritizing the information in accordance with particular view numbers includes using only ordering information, for particular operations, having a highest available view number and disregarding ordering information, for particular operations, where a view number is lower than that of other available ordering information.
8. The network of replicated servers of claim 1, wherein the length of time between when the non-leader informs the leader that the sufficient number of server replicas have received states that were broadcasted by the sufficiently large subset of the plurality of server replicas and when knowledge of the official state has been received by the non-leader is finite and measurable with respect to network conditions when the leader is functioning correctly.
9. The network of replicated servers of claim 8, wherein the network conditions are assessed by the server replicas by monitoring roundtrip times of messages sent to each other.
10. The network of replicated servers of claim 1, wherein the information prioritized in accordance with said view numbers is bounded to a particular quantity when the server replicas experience cascading failures.
11. The network of replicated servers of claim 1, wherein the view change protocol is tolerant of up to a number f of the server replicas experiencing Byzantine faults where the total number of server replicas is at least 3f+1.
12. A method for performing view change in a system of replicated servers providing a service, comprising:
executing a view change protocol after a leader is elected from among a plurality of server replicas in accordance with a leader election protocol for coordinating ordering of operations among the plurality of server replicas, the remainder of the plurality of server replicas being non-leaders, each iteration of the view change protocol corresponding to a unique view number;
broadcasting server replica states, from each server replica, and determining when a sufficient number of server replicas have received states that were broadcasted by a sufficiently large subset of the plurality of server replicas by the exchange of information between the non-leaders;
informing the leader when it is determined that the sufficient number of server replicas have received states that were broadcasted by the sufficiently large subset of the plurality of server replicas;
selecting an official state from among the states broadcast by the server replicas and broadcasting the selection of the official state to the non-leaders;
cooperating among the server replicas to agree upon the official state selected by the leader and to order operations not ordered as part of the official state, said cooperation including the exchange of information associated with particular view numbers, wherein said information is prioritized in accordance with said view numbers; and
monitoring a length of time between when the non-leader informs the leader that the sufficient number of server replicas have received states that were broadcasted by the sufficiently large subset of the plurality of server replicas and when knowledge of the official state has been received by the non-leader, and executing the leader election protocol to elect a new leader when it is determined that the monitored length of time is greater than a threshold value that is dependent upon current network conditions.
13. The method of claim 12, additionally comprising:
directing each server replica to cooperate with the other server replicas to order operations not ordered as part of the official state, said cooperation including the exchange of information associated with particular view numbers, wherein said information is prioritized in accordance with said view numbers.
14. The method of claim 12, wherein the operations whose order is coordinated by the leader include client queries or requests to be processed by the server replicas.
15. The method of claim 12, wherein the state of each of the server replicas is dependent upon what operations were executed by the respective server replica or in what order those operations were executed in.
16. The method of claim 12, wherein the server replicas execute a checkpoint protocol for enabling the server replicas to generate provably-correct checkpoints of their state and then discard messages used to order operations reflected within the state.
17. The method of claim 12, wherein prioritizing the information in accordance with particular view numbers includes using only ordering information, for particular operations, having a highest available view number and disregarding ordering information, for particular operations, where a view number is lower than that of other available ordering information.
18. The method of claim 12, wherein the length of time between when the non-leader informs the leader that the sufficient number of server replicas have received states that were broadcasted by the sufficiently large subset of the plurality of server replicas and when knowledge of the official state has been received by the non-leader is finite and measurable with respect to network conditions when the leader is functioning correctly.
19. The method of claim 18, wherein the network conditions are assessed by the server replicas by monitoring roundtrip times of messages sent to each other.
20. The method of claim 12, wherein the information prioritized in accordance with said view numbers is bounded to a particular quantity when the server replicas experience cascading failures.
21. The method of claim 12, wherein the view change protocol is tolerant of up to a number f of the server replicas experiencing Byzantine faults where the total number of server replicas is at least 3f+1.
22. A network of replicated servers providing a service, comprising:
a plurality of server replicas;
a leader elected from among the plurality of server replicas, the remainder of the plurality of server replicas being non-leaders; and
a view change protocol executed by the plurality of server replicas after the election of the leader,
wherein the view change protocol:
directs each server replica to cooperate with the other server replicas to determine information pertaining to the state of the server replicas and to send said information pertaining to the state of the server replicas to the leader;
directs the leader to select an official state using the information pertaining to the state of the server replicas received from the server replicas and to transmit the selection of the official state to the non-leaders;
directs each server replica to cooperate with the other server replicas to order operations not ordered as part of the official state; and
directs the non-leaders to monitor a length of time between when the non-leader sends said information pertaining to the state of the server replicas to the leader and when the selection of the official state is received from the leader, and to elect a new leader when it is determined that the monitored length of time is greater than a threshold value that is dependent upon current network conditions.