Abstract: The state of a workflow application in a distributed computing environment can be reconstructed by replaying previously executed portions of the workflow application. Embodiments maintain non-serialized event data relating to workflow history and use the data to determine subsequent actions to take in order to advance the workflow. In some embodiments, workflow instances can be serialized in order to create a checkpoint.

Abstract: A multi-tiered encryption system efficiently regulates the use of encryption keys to encrypt and decrypt data. The system can include one or more encryption tiers. Each encryption tier can include a computing node programmed to service encryption and/or decryption requests and a key store to store encryption keys. At a root encryption tier, an unencrypted root encryption key can be stored in the key store. Each subsequent encryption tier includes encryption keys that are encrypted by encryption keys stored at a lower encryption tier. The encryption tiers collectively implement an encryption policy in which keys are automatically created and rotated such that a requesting device can request encryption services from the multi-tiered encryption system and receive the encryption services independent of key creation or key rotation and without access to the unencrypted root encryption key.

Abstract: Systems and methods are described to provide fault tolerant folded Clos networks. A folded Clos network is disclosed including a set of tier 1 routers interconnected with a set of tier 2 routers. Tier 1 routers are configured to view a set of tier 2 routers as a single aggregate router. Accordingly, tier 1 routers are unaware of faults between tier 2 routers and additional tier 1 routers. A throwback router is connected to each tier 2 router to facilitate handling of data under such fault conditions. When a tier 2 router receives undeliverable data, the data is passed to a throwback router, which retransmits the data to an additional tier 2 router. Data that is retransmitted multiple times can be disregarded by the throwback router.

Abstract: A test document associated with a workflow definition is obtained, the test document including an input for an action of the workflow definition and an expected state for the workflow definition based on the input. The input is delivered for the action of a workflow instance, the workflow instance being an instance of the workflow definition executed by a workflow engine, and the action determined based upon a present state of the workflow instance. A next state of the workflow instance is obtained, where the next state is determined by the workflow engine based upon the present state, the action and the input. The next state of the workflow instance is compared to the expected state of the test document.

Abstract: Systems and methods for managing requesting routing functionality associated with resource requests for one or more resources associated with a content provider are provided. The request routing functionality can correspond to the processing of domain name service (“DNS”) requests for resources by computing devices and the resolution of the DNS requests by the identification of a network address of a computing device that will provide the requested resources. Based on the processing resource requests initiated by a client computing device, a CDN service provider can obtain performance information from client computing devices and correlate the performance information into a prioritized list for classes of client computing devices. The prioritized list can be utilized in resolving subsequent DNS queries.

Abstract: Techniques for utilizing a pool of human workers along with an automated classification feedback loop for identifying documents that meet certain criteria. As described herein, a requestor that desires to locate documents that meet certain specified criteria may first program a classifier with the specified criteria. The requestor may also determine the desired classes into which the classifier will categorize documents that are run against the classifier. The requestor may then locate one or more documents that represent each of the determined classes and then train the classifier using the documents. Thereafter, the requestor may publish a request to a pool of human workers soliciting documents meeting the criteria. Each of the documents may be run against the trained classifier and passed onto the requestor for further analysis if the classifier categorizes the respective document as acceptable.

Abstract: Disclosed are various embodiments for a trust establishment application. Machine instances executed in the same computing environment generate side channel patterns embodying data identifying themselves as trusted machine instances. The side channel patterns are detected to determine which machine instances are trusted. An operational mode of a machine instance is configured as a function of whether a quorum of trusted machine instances are executed in the computing environment.

Abstract: Disclosed are various embodiments for an ingestion process modifying digital items. A computing system receives an uploaded digital item configured to communicate with a testing server application when executed. The ingestion process reconfigures the digital item to communicate with a production server application when executed.

Abstract: High-speed processing of packets to, and from, a virtualization environment can be provided while utilizing hardware-based segmentation offload and other such functionality. A hardware vendor such as a network interface card (NIC) manufacturer can enable the hardware to support open and proprietary stateless tunneling in conjunction with a protocol such as single root I/O virtualization (SR-IOV) in order to implement a virtualized overlay network. The hardware can utilize various rules, for example, that can be used by the NIC to perform certain actions, such as to encapsulate egress packets and decapsulate packets.

Abstract: Features are disclosed for estimating a noise level using a variable step size. An acoustic echo canceller (AEC) may be configured to perform echo cancellation. The acoustic echo canceller may determine an estimated echo using a playback signal. The acoustic echo canceller also may determine an estimated error using the estimated echo and a microphone signal. A variable step size may be determined using the estimated error and the microphone signal. Noise reduction may be performed using the variable step size.

Abstract: Electronic devices can identify other nearby devices, and determine the relative positions of those devices, using a combination of techniques. Various devices are able to project one or more instances of a unique identifier, such as a barcode, which can be imaged by other devices. The devices also can communicate position and/or orientation information over a wireless sideband channel. By combining the information relating to the projected identifier with information collected over the sideband channel, devices can automatically determine the location of various devices and associate a user or device identity with those devices. A user of a device then can view relative locations of those devices on a display element, including information about the user of the device. Further, the relative position determinations can enable a user to perform certain functions with respect to another device based at least in part upon the position and/or identity of that device.

Abstract: A snapshot of a volume is taken by proactive uploading of scheduled snapshot data before the scheduled snapshot time has arrived. A volume snapshot schedule of once a day may be set up to a service provider using a speed-limited network connection. Using a determined upload speed of the network connection and a list of changes to the volume since a prior snapshot, a snapshot system may determine an appropriate time to start uploading volume data so that the snapshot may be completed at or after the scheduled snapshot time. By using the list of changes and available bandwidth of the network connection, the snapshot may be completed earlier than had it been started at the time of the snapshot and the available bandwidth of the network connection may be more efficiently used.

Abstract: Disclosed are various embodiments for presenting content items that are related to media items that are currently being consumed by a user. A media item in a stream of media items being presented to a client is identified. A content item that is relevant to the media item is determined. An entry is added to the entries of a relevant content listing. The entry includes a link to the content item. The entries in the relevant content listing are arranged in a time-based sequence such that the at least one entry correlates to a sequence of playback in the client of a plurality of media files. The relevant content listing is updated in a user interface that is being presented to the user.

Abstract: Methods and apparatus for unified account metadata management are disclosed. A storage medium stores program instructions that when executed on a processor generate a graph representation of metadata associated with a client account of a provider network. At least a portion of the metadata is obtained using an internal mechanism of the provider network. The graph comprises a plurality of nodes (representing resources associated with the client account) and a plurality of edges (representing configuration relationships). The instructions when executed provide a visualization of resources and configuration relationships of the graph; and in response to a graphical interaction with the visualization, issue a command to a network-accessible service of the provider network to implement a configuration modification associated with a resource represented in the graph.

Abstract: An inventory item to be picked may be selected along with an inventory location (e.g., storage bin) storing a particular unit of the item among a units of heterogeneous items also stowed in the inventory location. One or more images of the inventory location may be obtained and analyzed to determine a position of the unit of the item. Instructions may be sent to direct a device to illuminate the determined position of the unit of the item, and pick instructions may be sent to the same or a different the device. A device may receive the position instructions from a control system, and illuminate the determined position of the unit of the item within the inventory location. The pick instructions may direct an agent or mobile storage bin to a particular location and direct the agent to pick the unit of the item from the illuminated position.

Abstract: A system that implements a distributed lock service may include a failure detector for servers and sessions, and may track the state of sessions on a per-client-connection basis. It may include an external lock information database that stores lock state information and that supports a higher write throughput rate than a distributed state manager. Each database record may store an identifier of a session during which a lock on a respective item was obtained (if any) and a staleness indicator. A distributed state manager may maintain a session identifier and a respective staleness indicator for each established session, and may push updates to this session information to interested client processes, which may cache the information. A client process wishing to lock an item may determine whether it can do so dependent on the information in a corresponding database record and on its own cached session information.

Abstract: An audio-based system may perform dynamic level adjustment by detecting voice activity in an input signal and evaluating voice levels during periods of voice activity. The current voice level is compared to a plurality of thresholds to determine a corresponding gain strategy, and the input signal is scaled in accordance with this gain strategy. Further adjustment to the signal is performed to reduce output clipping that might otherwise be produced.

Abstract: A system that implements a data storage service may store data on behalf of storage service clients. The system may maintain data in multiple replicas of partitions that are stored on respective computing nodes in the system. A master replica for a replica group may increment a membership version indicator for the group, and may propagate metadata (including the membership version indicator) indicating a membership change for the group to other members of the group. Propagating the metadata may include sending a log record containing the metadata to the other replicas to be appended to their respective logs. Once the membership change becomes durable, it may be committed. A replica attempting to become the master of a replica group may determine that another replica in the group has observed a more recent membership version, in which case logs may be synchronized or snipped, or the attempt may be abandoned.

Abstract: Embodiments may include a load balancer configured to, for a given packet received from a remote client, select a host computer of a plurality of host computers according to a load balancing protocol, the selection based on load information updates received from the plurality of host computers. Each load information update may indicate a measure of the respective host computer's capacity to service additional connections with remote clients. The load balancer may provide the given packet to the selected host computer for processing by an application component on the selected host computer, and subsequent to determining that a specific application component on one of the plurality of host computers does not have capacity for additional connections based on the load information updates, continue to send packets for existing connections serviced by the specific application component to the respective host computer without sending packets for new connections to that host computer.

Abstract: During execution of a program, a code patching component may insert a redirection patch into a native-code representation of the program. The code patching component may identify a patch area in the native-code representation, copy existing code from the patch area to another location for subsequent emulation by a trap handler, determine the number of instructions and type of native-code elements within the patch area, and replace native-code elements in the patch area with native-code elements representing a jump type instruction and a target address argument for the jump type instruction (directly or indirectly indicating the location of new code that replaces the code in the patch area). The target address argument may be determined by the code patching component based on the program's characteristics, and may include a collection of elements representing existing code, trap type instructions, NOP type instructions, or arbitrary values.