Abstract: Customers of a shared-resource environment can provision resources in a fine-grained manner that meets specific performance requirements. A customer can provision a data volume with a committed rate of Input/Output Operations Per Second (IOPS) and pay only for that commitment (plus any overage), and the amount of storage requested. The customer will then at any time be able to complete at least the committed rate of IOPS. If the customer generates submissions at a rate that exceeds the committed rate, the resource can still process at the higher rate when the system is not under pressure. Even under pressure, the system will deliver at least the committed rate. Multiple customers can be provisioned on the same resource, and more than one customer can have a committed rate on that resource. Customers without committed or guaranteed rates can utilize the uncommitted portion, or committed portions that are not being used.

Abstract: Transaction requests may be ordered in a distributed database according to an independently assigned sequence. Different distributed system nodes, such as a transaction coordinator and a storage node may independently assign sequence numbers to requests to access a distributed database. A storage node may receive the request from a transaction coordinator with an assigned sequence number and another request to which the storage node may assign a sequence number. The storage node can then order performance of the requests based on the sequence numbers.

Abstract: Techniques are described for managing communications for a managed virtual computer network overlaid on a distinct substrate computer network, including for communications involving computing nodes of the managed virtual computer network that use an alternative addressing scheme to direct network packets and other network communications to intended destination locations by using textual network node monikers instead of numeric IP addresses to represent computing nodes at a layer 3 or “network layer” of a corresponding computer networking stack in use by the computing nodes. The techniques are provided without modifying or configuring the network devices of the substrate computer network, by using configured modules to manage and modify communications from the logical edge of the substrate network.

Abstract: Systems and methods dynamically manage replicas of data sets. A collection of data stores is used to redundantly store one or more replicas of one or more data sets. The replicas may be used to respond to read requests from multiple sources. Upon identification of a need to allocate storage space to a data object, space used by one or more of the replicas is allocated to the data object. Various parameters may be utilized in the selection of one or more replicas whose storage space can be allocated to the data object. The parameters may be based at least in part on characteristics of the one or more data sets relative to one another.

Abstract: A first role manager of a distributed service determines that a leadership assignment decision is to be made with respect to a particular node of the service. The first role manager identifies a particular role indicator value from a first subset of a set of role indicator values according to a value selection order of a role assignment policy of the service. The first role manager is not permitted to assign values from a different subset of the first set of role indicator values. The particular role indicator value is transmitted to the particular node, enabling the particular node to fulfill at least a first category of service requirements corresponding to the role of leader node.

Abstract: Techniques are described for managing communications for a managed virtual computer network overlaid on a distinct substrate computer network, including for communications involving computing nodes of the managed virtual computer network that use an alternative addressing scheme to direct network packets and other network communications to intended destination locations by using textual network node monikers instead of numeric IP addresses to represent computing nodes at a layer 3 or “network layer” of a corresponding computer networking stack in use by the computing nodes. The techniques are provided without modifying or configuring the network devices of the substrate computer network, by using configured modules to manage and modify communications from the logical edge of the substrate network.

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: 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: A geographically distributed system using a hybrid, multi-master design is disclosed. The system may use global tables, for which both reads and writes may be performed locally, but with a single region serving as a master region. All strongly consistent reads and writes may be sent to the master region, whereas eventually consistent reads and writes may be performed in any region with a replica. The master region may not be statically assigned but may move from region to region. The master region may be assigned manually by client preference or may be assigned and updated automatically based on the time of day or workload characteristics.

Abstract: Commitments against various resources can be dynamically adjusted for customers in a shared-resource environment. A customer can provision a data volume with a committed rate of Input/Output Operations Per Second (IOPS) and pay only for that commitment (plus any overage), for example, as well as the amount of storage requested. The customer can subsequently adjust the committed rate of IOPS by submitting an appropriate request, or the rate can be adjusted automatically based on any of a number of criteria. Data volumes for the customer can be migrated, split, or combined in order to provide the adjusted rate. The interaction of the customer with the data volume does not need to change, independent of adjustments in rate or changes in the data volume, other than the rate at which requests are processed.

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: 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: 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: 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: 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: 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 request to copy at least a portion of a first network that includes a first set of devices is received, the request including one or more filtering criteria, with at least one of the one or more filtering criteria specifying a tag assigned to a device of the first set of devices. At least the portion of the first network is copied by causing the system to create, according to the one or more filtering criteria, a second network by causing a second set of devices to be configured to be duplicative of devices of the first set of devices that are assigned the tag specified by the filtering criteria.

Abstract: Commitments against various resources can be dynamically adjusted for customers in a shared-resource environment. A customer can provision a data volume with a committed rate of Input/Output Operations Per Second (IOPS) and pay only for that commitment (plus any overage), for example, as well as the amount of storage requested. The customer can subsequently adjust the committed rate of IOPS by submitting an appropriate request, or the rate can be adjusted automatically based on any of a number of criteria. Data volumes for the customer can be migrated, split, or combined in order to provide the adjusted rate. The interaction of the customer with the data volume does not need to change, independent of adjustments in rate or changes in the data volume, other than the rate at which requests are processed.

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.