Abstract: A system that implements a scalable data storage service may maintain tables in a non-relational data store on behalf of clients. The system may provide a Web services interface through which service requests are received, and an API usable to request that a table be created, deleted, or described; that an item be stored, retrieved, deleted, or its attributes modified; or that a table be queried (or scanned) with filtered items and/or their attributes returned. An asynchronous workflow may be invoked to create or delete a table. Items stored in tables may be partitioned and indexed using a simple or composite primary key. The system may not impose pre-defined limits on table size, and may employ a flexible schema. The service may provide a best-effort or committed throughput model. The system may automatically scale and/or re-partition tables in response to detecting workload changes, node failures, or other conditions or anomalies.

Abstract: When providing a user with native access to at least a portion of device hardware, the user can be prevented from modifying firmware and other configuration information by controlling the mechanisms used to update that information. In some embodiments, an asymmetric keying approach can be used to encrypt or sign the firmware. In other cases access can be controlled by enabling firmware updates only through a channel or port that is not exposed to the customer, or by mapping only those portions of the hardware that are to be accessible to the user. In other embodiments, the user can be prevented from modifying firmware by only provisioning the user on a machine after an initial mutability period wherein firmware can be modified, such that the user never has access to a device when firmware can be updated. Combinations and variations of the above also can be used.

Abstract: A system for performing computing operations in a data center includes one or more sets of computer systems, one or more primary power systems, and a reserve power system. The primary power systems include at least one power distribution unit that supplies power to at least one of the sets of computer systems. The reserve power system automatically supplies power to at least one of the sets of computer systems if a condition is met (such as a failure of the primary power system).

Abstract: A cost-effective, durable and scalable archival data storage system is provided herein that allow customers to store, retrieve and delete archival data objects, among other operations. For data storage, in an embodiment, the system stores data in a transient data store and provides a data object identifier may be used by subsequent requests. For data retrieval, in an embodiment, the system creates a job corresponding to the data retrieval and provides a job identifier associated with the created job. Once the job is executed, data retrieved is provided in a transient data store to enable customer download. In various embodiments, jobs associated with storage, retrieval and deletion are scheduled and executed using various optimization techniques such as load balancing, batch processed and partitioning. Data is redundantly encoded and stored in self-describing storage entities increasing reliability while reducing storage costs. Data integrity is ensured by integrity checks along data paths.

Abstract: A system that implements a scalable data storage service may maintain tables in a non-relational data store on behalf of clients. The system may provide a Web services interface through which service requests are received, and an API usable to request that a table be created, deleted, or described; that an item be stored, retrieved, deleted, or its attributes modified; or that a table be queried (or scanned) with filtered items and/or their attributes returned. An asynchronous workflow may be invoked to create or delete a table. Items stored in tables may be partitioned and indexed using a simple or composite primary key. The system may not impose pre-defined limits on table size, and may employ a flexible schema. The service may provide a best-effort or committed throughput model. The system may automatically scale and/or re-partition tables in response to detecting workload changes, node failures, or other conditions or anomalies.

Abstract: Systems and methods for secure deletion of data items in a storage system may support the deletion of stored data item. In response to a storage request, a storage manager may generate a key corresponding to the data item to be stored and encrypt the data item before storing the data item in a data store. The key may be stored in an index comprising metadata corresponding to the data item. In response to a delete request, the storage system may determine the corresponding metadata entry in the index and remove the key corresponding to the data item without accessing the data item.

Abstract: A cost-effective, durable and scalable archival data storage system is provided herein that allow customers to store, retrieve and delete archival data objects, among other operations. For data storage, in an embodiment, the system stores data in a transient data store and provides a data object identifier may be used by subsequent requests. For data retrieval, in an embodiment, the system creates a job corresponding to the data retrieval and provides a job identifier associated with the created job. Once the job is executed, data retrieved is provided in a transient data store to enable customer download. In various embodiments, jobs associated with storage, retrieval and deletion are scheduled and executed using various optimization techniques such as load balancing, batch processed and partitioning. Data is redundantly encoded and stored in self-describing storage entities increasing reliability while reducing storage costs. Data integrity is ensured by integrity checks along data paths.

Abstract: Customers of shared resources in a multi-tenant environment can have token buckets allocated that have an associated depth and fill rate, with each token enabling the customer to obtain an amount of work from a shared resource. A resource management system can monitor one or more system or output metrics, and can adjust a global fill rate based at least in part upon values of the monitored metrics. Such an approach can provide a fair distribution of work among the customers, while ensuring that the metrics stay within acceptable ranges and there are no drastic changes in performance levels of the system. The fill rate can update dynamically with changes in the monitored parameters, such that the system can float near an equilibrium point. Commitments for specific minimum service levels also can be met.

Abstract: Customers of shared resources in a multi-tenant environment can have token buckets allocated that have an associated depth and fill rate, with each token enabling the customer to obtain an amount of work from a shared resource. A resource management system can monitor one or more system or output metrics, and can adjust a global fill rate based at least in part upon values of the monitored metrics. Such an approach can provide a fair distribution of work among the customers, while ensuring that the metrics stay within acceptable ranges and there are no drastic changes in performance levels of the system. The fill rate can update dynamically with changes in the monitored parameters, such that the system can float near an equilibrium point. Commitments for specific minimum service levels also can be met.

Abstract: The state of firmware for devices on a provisioned host machine can be validated independent of the host CPU(s) or other components exposed to the user. A port that is not fully exposed or accessible to the user can be used to perform a validation process on firmware without accessing a CPU of the host device. The firmware can be scanned and a hashing or similar algorithm can be used to determine validation information, such as hash values, for the firmware, which can be compared to validation information stored in a secure location. If the current and stored validation information do not match, one or more remedial actions can be taken to address the firmware being in an unknown or unintended state.

Abstract: A data center includes an air handling system and a thermal energy receptacle system. The air handling system moves air across heat producing components of electrical systems in the data center. The thermal energy receptacle system is coupled to the air handling system. The thermal energy receptacle system includes one or more heat exchangers that exchange heat between air moving through the air handling system and a fluid, one or more phase change material modules including phase change material, and a fluid transport system that transports fluid between the phase change material modules and the heat exchangers. The thermal energy receptacle system transfers heat from air passing over the one or more heat exchangers to at least one of the phase change material modules such that at least a portion of the phase change material changes phase.

Abstract: A method of operating an automatic transfer switch to switch an electrical load from one power source to another power source includes measuring one or more characteristics of a switching circuit in the automatic transfer switch. A value of one or more timing variables is determined based on the measured characteristics of the switching circuit. The switching circuit is operated to close relays in the automatic transfer switch. The timing of closing of the relays is based on the value of the timing variables.

Abstract: Methods and apparatus for datacenter power management optimization are disclosed. Metrics, including workload data, thermal measurements and the like are collected from numerous endpoints within a datacenter. System profiles of a plurality of servers, and application workload profiles for various workloads, are stored. Based on analysis of collected metrics, power optimization operations comprising either workload scheduling operations, power configuration change operations, or both, are initiated.

Abstract: Methods and apparatus for equitable distribution of excess shared-resource throughput capacity are disclosed. A first and a second work target are configured to access a shared resource to implement accepted work requests. Admission control is managed at the work targets using respective token buckets. A first metric indicative of the work request arrival rates at the work targets during a time interval, and a second metric associated with the provisioned capacities of the work targets are determined. A number of tokens determined based on a throughput limit of the shared resource is distributed among the work targets to be used for admission control during a subsequent time interval. The number of tokens distributed to each work target is based on the first metric and/or the second metric.

Abstract: A method of operating an automatic transfer switch to switch an electrical load from one power source to another power source includes measuring one or more characteristics of a switching circuit in the automatic transfer switch. A value of one or more timing variables is determined based on the measured characteristics of the switching circuit. The switching circuit is operated to close relays in the automatic transfer switch. The timing of closing of the relays is based on the value of the timing variables.

Abstract: When providing a user with native access to at least a portion of device hardware, the user can be prevented from modifying firmware and other configuration information by controlling the mechanisms used to update that information. In some embodiments, an asymmetric keying approach can be used to encrypt or sign the firmware. In other cases access can be controlled by enabling firmware updates only through a channel or port that is not exposed to the customer, or by mapping only those portions of the hardware that are to be accessible to the user. In other embodiments, the user can be prevented from modifying firmware by only provisioning the user on a machine after an initial mutability period wherein firmware can be modified, such that the user never has access to a device when firmware can be updated. Combinations and variations of the above also can be used.

Abstract: Methods and apparatus for datacenter power management optimization are disclosed. Metrics, including workload data, thermal measurements and the like are collected from numerous endpoints within a datacenter. System profiles of a plurality of servers, and application workload profiles for various workloads, are stored. Based on analysis of collected metrics, power optimization operations comprising either workload scheduling operations, power configuration change operations, or both, are initiated.

Abstract: Methods and apparatus for equitable distribution of excess shared-resource throughput capacity are disclosed. A first and a second work target are configured to access a shared resource to implement accepted work requests. Admission control is managed at the work targets using respective token buckets. A first metric indicative of the work request arrival rates at the work targets during a time interval, and a second metric associated with the provisioned capacities of the work targets are determined. A number of tokens determined based on a throughput limit of the shared resource is distributed among the work targets to be used for admission control during a subsequent time interval. The number of tokens distributed to each work target is based on the first metric and/or the second metric.

Abstract: A system that implements a scalable data storage service may maintain tables in a non-relational data store on behalf of clients. The system may provide a Web services interface through which service requests are received, and an API usable to request that a table be created, deleted, or described; that an item be stored, retrieved, deleted, or its attributes modified; or that a table be queried (or scanned) with filtered items and/or their attributes returned. An asynchronous workflow may be invoked to create or delete a table. Items stored in tables may be partitioned and indexed using a simple or composite primary key. The system may not impose pre-defined limits on table size, and may employ a flexible schema. The service may provide a best-effort or committed throughput model. The system may automatically scale and/or re-partition tables in response to detecting workload changes, node failures, or other conditions or anomalies.

Abstract: Methods and apparatus for burst-mode admission control using token buckets are disclosed. A work request (such as a read or a write) directed to a work target is received. Based on a first criterion, a determination is made that the work target is in a burst mode of operation. A token population of a burst-mode token bucket is determined, and if the population meets a second criterion, the work request is accepted for execution.