Abstract: Users intending to launch instances or otherwise access virtual resources in a multi-tenant environment can specify a launch configuration. For each type of instance or each type of user, at least one launch configuration is created that includes parameters and values to be used in instantiating an instance of that type, the values being optimized for the current environment and type of instance. Launch configurations can be optimized for different types of users, such as to account for security credentials and access levels. Such an approach enables users to launch instances by contacting the resource provider directly without need for a proxy, which can function as a choke point under heavy load. The use of an appropriate launch configuration can be enforced for any type of user at any level, such as at the sub-net level, by modifying a request that does not specify an appropriate launch configuration.

Abstract: A resource manager arranges the resources in a computer system into one or more resource pools. The resource manager allocates a number of active resources and a number of backup resources to a particular resource pool. For each resource managed by the resource manager, the resource manager acquires information that describes the capacity and reliability of the resource. Capacity and reliability information for the particular resource pool is determined based on the capacity and reliability information associated with the resources assigned to the pool. In response to a request, the resource manager may provide an application with resources from several resource pools. The likelihood that the resource manager will be able to provide sufficient resources to the application may be determined based at least in part on the reliability information associated with the several resource pools.

Abstract: A partitioning policy for materializing writes indicated in journal entries of a multi-data-store database is determined. The policy indicates a partitioning attribute of a data object. A write applier associated with a materialization node of the database processes journal entries according to the partitioning policy. If the value of the partitioning attribute associated with a write of a particular journal entry indicates that the write belongs to a partition materialized at the materialization node, the write applier propagates the write to the materialization node for storage at the node's storage devices.

Abstract: Systems with multiple components managing storage may implement efficient storage reclamation. A storage reclamation event may be detected for a system component. An indication to a request dispatching mechanism may be made which indicates that the system component is unable to perform further tasks in order to perform storage reclamation. A storage reclamation operation, such as a stop-the-world garbage collection technique, or a service process restart may be performed to reclaim at least some storage. Upon completion of the storage reclamation operation, an indication may be made to the request distribution mechanism that the service process has resumed performing tasks for the system. In some embodiments, a gossip protocol communicating availability information to different nodes of a distributed system may provide information to schedule storage reclamation operations at different compute nodes of the distributed system.

Abstract: A pipeline management service improves the operation of a processing pipeline by monitoring the operation of one or more journal services within the processing pipeline, and adjusting operational parameters of the one or more journal services. In various examples, the pipeline management service determines a model of the processing pipeline by identifying the producers and consumers associated with each of the one or more journal services, and determines a processing flow through the one or more journal services based at least in part on the identities of the associated producers and consumers. The pipeline management service acquires backlog information from each of the one or more journal services, and may adjust the operational parameters of a journal service associated with an identified processing bottleneck. In some examples, the pipeline management service adjusts capacity and reliability parameters of the one or more journal services to improve the operation of the processing pipeline.

Abstract: An analytics tool of a journal-based multi-data-store database obtains respective rejection cause descriptors for a set of transactions rejected by the journal manager of the database due to read-write conflicts. A particular rejection cause descriptor indicates a query predicate used for a read set of a transaction request which was rejected by a journal manager of the database due to a read-write conflict between the read set and a previously-committed transaction. The analytics tool prepares a database contention analysis using the rejection cause descriptors, and transmits the analysis to a client.

Abstract: A particular node of a journal-based multi-node distributed storage system requests the addition of an acceptability verification request entry to the journal, indicating a proposed state change of the system. The particular node examines contents of entries added to the journal after the acceptability verification request entry. After determining that a targeted set of acceptability verification response entries have been added to the journal, indicating that the potential state change meets acceptance criteria at respective other nodes of the system, the particular node requests an addition of a committed transaction entry to the journal, indicating an approval of the proposed state change.

Abstract: Methods and systems for provisioning computing resource instances among implementation resources based on trust to reduce interference between computing resource instances implemented by the same implementation resources. In an embodiment, a trust rating is determined for a computing resource instance based at least in part on one or more trust factors. The suitability of an implementation resource to implement the given computing resource instance may be evaluated based at least in part on the trust rating of the computing resource instance and a trust rating of the implementation resource. In some embodiments, the trust rating of the implementation resource may be predefined or based on trust ratings of computing resource instances that are currently implemented by the implementation resource. An implementation resource may be selected to implement the computing resource instance based at least in part on its suitability thus determined.

Abstract: A journaled database system may comprise data nodes that maintain a collection of data structured in accordance with a schema. A change to the schema may be applied by a journal module while a journal consumer continues to operate using a prior version of the schema. A buffer may be formed and have stored therein records describing state change instructions according to the prior view of the schema. An index of correspondence between the records in the buffer and in the source journal may be maintained.

Abstract: A forking coordinator of a journal-based multi-data-store database determines that a forking criterion for a first journal has been met. The coordinator stores an indication that processing of transaction requests directed to a particular subset of the database is suspended. The coordinator instantiates a second journal for storing committed transaction entries for the particular subset. Metadata of the second journal indicates that transaction entries with sequence numbers in a particular range are stored in the first journal. The coordinator stores an indication that transaction processing associated with the particular subset of the system is to be resumed using the second journal.

Abstract: Systems and methods for attesting to information about a computing resource involve electronically signed documents. For a computing resource, a document containing information about the resource is generated and electronically signed. The document may be provided to one or more entities as an attestation to at least some of the information contained in the document. Attestation to information in the document may be a prerequisite for performance of one or more actions that may be taken in connection with the computing resource.

Abstract: A test coordinator for an application whose data is to be stored at a journal-based multi-data-store database using an optimistic concurrency control protocol identifies a test descriptor. The test descriptor indicates a particular order of a plurality of events associated with the application's data, such as reads from various data stores and propagations of committed writes from the database journal to the data stores. The test coordinator uses a set of control mechanisms to cause the events to occur in a selected execution environment in the particular order, and stores an indication of a state reached by the application in response to the events.

Abstract: A plurality of virtual computing resources is detected to have been provisioned. Credentials are distributed to the plurality of virtual computing resources. A credentials map that maps the credentials to the plurality of virtual computing resources is updated. The credentials for the plurality of virtual computing resources are activated to enable the plurality of virtual computing resources to use the credentials to authenticate to a second computer system that manages a resource service, with the credentials being inaccessible to resources of the resource service. A virtual computing resource of the plurality of virtual computing resources is detected to been deprovisioned, and the credentials for the virtual computing resource are deactivated.

Abstract: A journaled database system may comprise data nodes that maintain a collection of data structured in accordance with a schema. A change to the schema may be applied by a journal module while a journal consumer continues to operate using a prior version of the schema. A buffer may be formed and have stored therein records describing state change instructions according to the prior view of the schema. An index of correspondence between the records in the buffer and in the source journal may be maintained.

Abstract: A journal manager of a multi-data-store storage appends a committed transaction entry to a journal, indicating a state change which has been approved for commit using an optimistic concurrency control algorithm. A first representation of the state change is generated and stored at one materialization node. A different representation of the same state change, comprising at least one attribute for which a value is not included in the first representation, is generated and stored at a different materialization node.

Abstract: A materialization configuration request is received via a programmatic interface from a client of a journal-based multi-data-store database. The request indicates a partitioning rule to be used to select, for respective writes indicated in committed transaction entries of a journal, the materialization node at which the writes are to be stored. A control plane component of the database verifies that a set of materialization nodes corresponding to the partitioning rule has been established, and initiates the propagation of writes from the journal to the materialization nodes by respective write appliers.

Abstract: A data store manager of a multi-data-store journal-based database performs a sequential analysis of committed transaction entries of a journal. A particular entry includes a directive to determine a value of an attribute of a data object based on a result obtained from a value generator, and does not specify the value of the attribute. The data store manager determines the value using a local version of the value generator, and stores the value in a materialized version of the data object. In response to a programmatic read request, the data store manager provides the materialized version of the data object.

Abstract: A plurality of virtual computing resources is detected to have been provisioned. Credentials are distributed to the plurality of virtual computing resources. A credentials map that maps the credentials to the plurality of virtual computing resources is updated. The credentials for the plurality of virtual computing resources are activated to enable the plurality of virtual computing resources to use the credentials to authenticate to a second computer system that manages a resource service, with the credentials being inaccessible to resources of the resource service. A virtual computing resource of the plurality of virtual computing resources is detected to been deprovisioned, and the credentials for the virtual computing resource are deactivated.

Abstract: Aspects of provisioning computing units based on improved failure resiliency are described. In one embodiment, an infrastructure component shared between a pair of computing units is identified. A failure rate for the infrastructure component is obtained, and a failure probability for a class of assigned computing units is computed based in part on the failure rate. A spread request related to the class of assigned computing units is also received. In response to the spread request, an altered composition of computing units is determined, and a difference between a failure probability for the altered composition of computing units and the failure probability for the class of assigned computing units is computed. In one embodiment, when a spread score improvement value associated with the difference meets a spread criteria of the spread request, the altered composition of computing units may be provisioned for use.

Abstract: A materialization configuration request is received via a programmatic interface from a client of a journal-based multi-data-store database. The request indicates a partitioning rule to be used to select, for respective writes indicated in committed transaction entries of a journal, the materialization node at which the writes are to be stored. A control plane component of the database verifies that a set of materialization nodes corresponding to the partitioning rule has been established, and initiates the propagation of writes from the journal to the materialization nodes by respective write appliers.