Data expiration for stream storages

The described technology is generally directed towards fine-grained data event expiration in a streaming data storage system. An event to append is given an expiration period, and the expiration time for the events in a data stream or segment of a data stream is the largest expiration time among events in the data stream or segment. Different segments can have different expiration times for their events. In a segment comprising a group of events, a subgroup of expired events prior to a stream cut are deleted by an expiration task. For a subgroup of unexpired events prior to a stream cut, the expiration task retains (does not delete) the subgroup of events. If a scaling operation is performed on a segment, the new successor segment or segments inherit the largest expiration time of the predecessor segment or segments.

BACKGROUND

Contemporary data storage systems store data in a storage abstraction referred to as a stream. A stream is identified with a name, and can store continuous and potentially unbounded data; more particularly, a stream comprises a durable, elastic, append-only, sequence of stored events. New events are added to a tail (front) of a stream. One stream may be divided into one or more segments, with an event appended to a segment based on a routing key associated with the event that determines to which segment the event data is written.

Although a stream is potentially unbounded, storage resources are finite. Thus, events from a stream can be deleted from a head (back) of a stream. Not all stream data can simply be deleted, however, as data retention policies need to be followed for some types of data, typically for regulatory compliance or business reasons. Thus, only expired events can be deleted. However, in most scenarios it is not practical to maintain a separate expiration time for each event.

DETAILED DESCRIPTION

Various aspects of the technology described herein are generally directed towards implementing time-based data expiration in streaming data storage systems, in which expiration policy can be specified at the event level. Via the technology, different events in one data stream can have different expiration periods relative to other events in the same data stream. Note that this is in contrast to a data expiration period specified at the stream level, in which the administrator/application program is forced to choose the longest expiration period any event in the stream may have and use that expiration period as the stream expiration period; this normally results in too conservative data expiration in which events with a short expiration period are retained for too long.

The technology described herein further facilitates fine-grained, event level expiration times on a per-segment basis. As will be understood, because it is not practical to maintain an expiration time with each event and evaluate each such time for individual event expiration, in each segment the event with the greatest expiration time determines the expiration time for that segment. A segment's events can be automatically expired based on the given segment's expiration time.

It should be understood that any of the examples herein are non-limiting. For instance, virtually any stream-based data storage system may benefit from the technology described herein. As a more particular example, instead of tracking time for each event, a “stream cut object” or simply a “stream cut” refers to a specific position in the segment of a data stream on an event boundary; expired data is deleted from a stream cut boundary (rather than arbitrarily). A stream cut is associated with a time value, referred to as a stream cut expiration time. Other data stream storage systems can use a similar concept, or can use timestamped data; notwithstanding, as will be understood, the technology described herein can be applied to any stream-based data storage mechanism. Thus, any of the embodiments, aspects, concepts, structures, functionalities or examples described herein are non-limiting, and the technology may be used in various ways that provide benefits and advantages in computing and data storage in general.

Reference throughout this specification to “one embodiment,” “an embodiment,” “one implementation,” “an implementation,” etc. means that a particular feature, structure, or characteristic described in connection with the embodiment/implementation can be included in at least one embodiment/implementation. Thus, the appearances of such a phrase “in one embodiment,” “in an implementation,” etc. in various places throughout this specification are not necessarily all referring to the same embodiment/implementation. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments/implementations.

FIG.1shows a streaming data storage system100that includes a segment store102that maintains and manages segments104(1)-104(n) of at least part of a data stream106. Note that the segments104(1)-104(n) can be distributed among segment store instances, such as distributed among different nodes of a node cluster.

In general, an event writer such as a streaming application program108sends data writes110comprising an event112into the streaming data storage system100via an application programming interface (API) of a client component114in one implementation. As described herein, an event112comprises a routing key, the event data (payload) and an expiration time for that event112. The application program108also can send stream cuts116and truncate requests118to the streaming storage system100, such as by identifying the stream for which truncation is requested, and specifying a particular stream cut.

More particularly, as set forth herein, a position in a stream at an event boundary is specified using a stream cut. The application program104can request association of a stream cut with a stream, as represented by block116. However, in the examples described herein, the system rather than the application program108causes generation of the stream cuts and automatically expires data. Thus, instead of (or in addition to) application-specified stream cuts, other stream cuts120can be generated automatically, such as periodically, by automated program(s)122or the like, e.g., a stream cut generator124. The automated program(s) can also send truncate requests126, such as when the stream reaches a size capacity limit and/or periodically, e.g., by an expiration task128, which in one implementation runs as a background task. As described herein, the automated programs (e.g., the stream cut generator124and/or the expiration task128can be operated by or incorporated into a controller130, that is, the controller130can generate stream cuts and run the expiration task128, such as periodically based on administrator-specified configuration policy data, which can include granularity (how often to generate a next stream cut). It is also feasible for the segment store102to perform automated truncation on its segments.

As described herein, the stream cuts for a stream can be considered a series of stream cuts. In one or more implementations, the stream cuts may be maintained as an auxiliary system stream132associated with the segments104(1)-104(n) of the data stream106.

As set forth above, deletion of individual events based on their individual expiration times is impractical for most streaming data storage use-cases. Stream truncation using stream cuts is practical, whereby the technology described herein uses bulk-mode data deletion by means of stream truncation (or discarding stream head events, or decapitation) of a subgroup of expired events prior to a stream cut.

To this end, information related to data expiration is associated with stream cuts, that is, there is an expiration time associated with each stream cut. When an expiration task reaches another stream cut, the expiration task compares the stream cut's expiration time to the current system time134; (note that the correct system time134can be obtained via use of the Network Time Protocol (NTP)). If the expiration time is in the future, the expiration task leaves the stream alone until next evaluation time. Otherwise the expiration truncates the stream using the stream cut, that is, deletes the subgroup of expired events that are prior to the stream cut.

For further granularity, a time-based expiration value (e.g., based on the system time134) can be associated with each stream cut and each segment, that is, the stream cut expiration time can be maintained on a per-segment basis, which as described herein depends on the events' expiration times in each segment. Thus, as described herein, each segment can have an associated expiration time, namely the maximum expiration time of any event prior to the stream cut in one implementation. When a stream is requested to be truncated, e.g., periodically and/or based on size, the expiration task128(or other system component) evaluates the specified stream cut, and for each segment, whether the segment's expiration time is in the future. If not in the future, the segment's events prior to the stream cut are deleted.

To determine an expiration time for a stream cut, respective expiration periods can be associated with respective individual events. There is no need to store per-event expiration periods to streams/segments, as an event's expiration period can be used at the event creation moment and discarded thereafter.

As represented inFIG.2A, when new event is created within a stream, the time the event is created is called the event creation time. An expiration policy can be specified for the event, which basically defines the expiration period for the event. The period starts at the moment the event is created, and the moment the period ends is called the event expiration time. The application does not need the event after its expiration time, so the system is expected to delete the event shortly thereafter to release the storage capacity it occupies.

More particularly, an expiration time can be calculated for an individual event at the moment of event creation using the following, for any event [i]:
event[i].expiration_time=event[i].creation_time+event[i].expiration_period

Then, as a stream cut has to protect the events that are ahead of the stream cut from a premature automatic deletion, the stream cut “inherits” the expiration times of a group of events. That is, as represented inFIG.2B, for a stream cut[j]:
stream_cut[j].expiration_time=max(event[i].expiration_time)
where the event[i]'s represent the group of events that were created before the j′th stream cut. Note that because of the max( ) function, the expiration time for a stream/segment looks like an “expiration front” that can move forward but cannot move backward.

As can be seen inFIG.2B, where a stream segment contains two events e1and e2with different creation times and different expiration periods, the expiration times of the events are also different. The stream cut, which was created after the two events, inherits the greater (the maximum/rightmost) expiration time, which is event e2's expiration time in this example. The stream can be auto-truncated by the expiration task using the stream cut only when the current system time is greater or equal to the stream cut's expiration time.

In one implementation, the segment store (the instance that manages a stream segment) calculates an expiration time for every new event, maintaining only the maximum expiration time for those the events within the segment. As shown inFIG.3, the maximum expiration time for a segment can be persisted with other segment metadata (attributes)334. When another stream cut is created, the stream cut gets the current segment's maximum expiration time as the stream cut's effective expiration time. For additional detail,FIG.3shows the segment event data336and stream cut's metadata338(described below), along with readers/reader groups340that read and process the events.

The segment store102is responsible for keeping track of the (longest) expiration time of the events in a segment. As set forth herein, the system does not need to store the expiration period or expiration time for each event (which would waste resources). Instead,FIG.4shows an implementation of example operations as to how the segment store102may maintain the expiration time for stream segments (so that the controller332can use that information to maintain in a stream cut).

At operation402ofFIG.4, the client component330receives an event E with an expiration period E.EP to be appended to the stream S. At operation404, the client330determines that the event E (based on its routing key has computation) is to be written to an active segment Sk. The client identifies the appropriate segment store instance (e.g.,102) that manages Sk, and sends the request to that segment store instance102at operation406.

At operation408, the segment store102receives the request to append E to Sk, with the current time being T. In one implementation, the event E's expiration time is therefore calculated as E.EXP:=T+E.EP; (although it is feasible for the event E's expiration time to be determined sooner). For the segment, the segment store102determines the segment Sk's expiration time metadata to be Sk.EXP:=Max(Sk.EXP, E.ET), that is, the segment Sk's expiration time is the longer of either the existing expiration time for that segment, or the new event's expiration time, as updated (if appropriate) via operation410.

Operation412appends the event E to the segment Sk. It should be noted that, in conjunction with appending the event E to the segment Sk, the segment store atomically updates Sk's metadata to ensure that Sk's expiration time is set as described in operation410as described above. The atomicity of operations410and412prevent a situation in which the segment's expiration time is updated before or after the event is persisted, then a controller request (as described above) may get incorrect/inconsistent information about Sk's length and expiration time, which could possibly lead to the premature deletion of events during an expiration operation.

Once these (atomic) operations410and412are done, when the controller332requests information as described herein (at operation408ofFIG.4), the segment store reads Sk's length and expiration time ET from its metadata and returns in response to the controller's request.

As shown inFIG.5, stream cuts divide a stream552into a sequence of stream fragments, where a stream fragment is the part of a stream between two successive stream cuts. There is a generally a plurality of events stored within each stream fragment, and these events may reside in different stream segments. Each new stream cut “closes” another stream fragment; as highlighted inFIG.5by the dashed oval554containing lines representing event boundaries in segments (represented inFIG.5as rectangles making up the stream552) corresponding to stream cut SC1. As shown via the event boundaries represented within the example dashed oval554, because each stream cut divides a stream into two parts, each such stream cut needs to cross those segments that were active at the time the stream cut was generated. As such, a stream cut's metadata comprises a collection of key-value groupings (e.g., Key=Segment, Value=offset within segment), with one such grouping for each segment that the stream cut crosses. Note that events may have very different expiration periods, and events of different types may have very different intervals. Thus, it is possible that a stream cut has an expiration time that was calculated not for some event from the last stream fragment, but for an event from a quite distant stream fragment.

Thus, as described herein and represented inFIG.3, a stream cut such as exemplified by the expanded stream cut SC1, the stream cut metadata338for each stream cut may include a set of groupings, e.g., segment name or identifier (ID) and offset within the segment (where the offsets are at an event boundaries in each active segment), along with the aforementioned stream cut expiration time (Key=segment, Value=offset within segment, Value=segment's expiration time), or as shown in the stream cut metadata338inFIG.3as, Segment_ID1, Offset J, Expiration_Time X, Segment_ID2, Offset K, Expiration_Time Y, and so on for each other segment; (note that the stream cut SC1 is for multiple segments in this example). Thus, a stream cut metadata338contains the offset locations (lengths) and expiration times of the various segments; a stream cut does not divide an event, but rather defines an event boundary for each segment.

Thus, when a stream is comprised of a set of segments, the system (the segment store102) maintains respective maximum expiration times for respective individual segments of the stream. As a result, at the moment another stream cut is created, different segments of one data stream likely have different maximum expiration times, as represented in the two-segment data stream ofFIG.6A, that is, the two segments s1 and s2, have different maximum expiration times. While it is straightforward to calculate a maximal maximum expiration time among the stream segments and make that value the stream expiration time (for all segments of the stream), a more fine-grained approach is to use composite expiration times for stream-cuts. The thick dashed line inFIG.6Adepicts the composite expiration times associated with the stream-cut, which can be thought of as the segment_id, expiration_time parts of the stream cut's groupings.

As shown inFIG.6B, when expiration times can be composite, the expiration task may determine that only a part of stream data associated with a stream-cut has expired. When this occurs, the expiration task can delete only the expired data and leave unexpired data in the segment, at least until the next expiration check. The expiration task is finished with a stream cut when the expiration task has deleted the entire group of expired data events, for each segment, ahead of the stream cut. After that, the system (the controller) is free to delete the stream cut as the stream cut is no longer needed.

InFIG.6B, the expiration task detects that the system (at time “now”) is in the middle between the two expiration times associated with the stream cut. Therefore, the expiration task deletes the subgroup of event data of only one stream segment, s2, which is the stream segment with the expiration time in the past. The segment data that is deleted is the subgroup of events of segment s2 from the previous head up to the stream-cut, moving the “new” segment head of s2 forward.

FIG.7shows example operations for generating a stream cut, beginning at operation702where the controller130begins stream cut generation-related operations, e.g., periodically. As represented by operation704and by the components and data structures ofFIG.3, the controller130inspects the stream metadata to determine the set of active segments342; (note that a segment that is scaled up or scaled down as described below is an inactive segment). The stream metadata that includes the active stream segments can be maintained in the segment store instance(s) and obtained by the controller therefrom, however it is understood that any suitable data structure accessible to the controller130can maintain a stream's active stream segment identifiers.

For each active segment Skin the active segment set of the stream S, (operations706,712and714), the controller130issues a request at operation708to the segment store334to obtain/retrieve the segment Sk's length and the segment Sk's expiration time, which are maintained as segment attributes334in the segment store102(as described herein and shown inFIG.3).

More particularly, the various segments' metadata (attributes334) may be stored in the segment store102, although it is feasible to store some of it in other suitable location(s) in any number of ways. Note that in one or more implementations, a segment store such as102already maintain some segment metadata/attributes (e.g., relating to Sk's length, truncation status, sealed status, how much of Skis in Tier 1 versus Tier 2 storage and so on, and thus for example, the segment store102may add to this this metadata to store the segment's expiration time as well, as shown in the segment attributes334inFIG.3.

In one implementation, at operation710the controller130sets the grouping for the selected segment Sk to the obtained information of {Segment ID, Offset, Expiration Time} of segment Sk. This is repeated for each other active segment via operations712and714. When the groupings are known, at operation716, the controller130writes the stream cut SC's {Segment ID, Offset, Expiration Time} groupings into the stream cut's metadata associated with the stream cut associated with Stream S, (e.g., the stream cut auxiliary stream132for the data stream106inFIG.1).

When a stream contains a relatively large number of segments, the graphical profile of the stream head (e.g.,FIG.6B) may be highly irregular. An administrator can use the fine-grained data expiration technology described herein to create more capacity-efficient systems, by generally having a group of events with similar expiration periods map to one segment, or a relatively small set of segments. This will operate to avoid having events with long lifetimes prevent the deletion of events with shorter lifetimes.

A stream is elastic in that segment(s) may be sealed and new segment(s) may replace them as successor segments(s) in a scaling event (a scale-up or scale-down event), such as automatically triggered (an auto-scaling operation) by the rate or size of event ingestion to a segment. Each scaling event creates a new epoch as described below.

In a scale-up event, an active segment is split into two or more newly created active segments referred to as successor segments; the segment that was split is referred to a predecessor segment, and is sealed in an atomic operation with the creation of the successor segments, whereby the predecessor segment is no longer an active segment. In a scale-down event, two or more active segments (the predecessor segments) are merged into a newly created active segment (the successor segment); the predecessor segments are sealed in an atomic operation with the creation of the successor segment, whereby the predecessor segments are no longer active segments.

FIG.8Ashows a stream with two auto-scaling operations that split a stream into three epochs (ep1-ep3). During a scale up event, segment s1 is split into segments s4 and s5, and segment s1 gets sealed. During a scale down event, segments s2 and s3 get merged into segment s6, and segments s2 and s3 get sealed.

As expiration times are determined at the segment level, this can be problematic when the segment(s) of a stream are sealed and become inactive due to a scaling event, because stream-cuts are only created for active stream segments. For example, consider that segment s1 inFIG.8Acontains an event with expiration time in the far future, while segments s4 and s5 contain events with rather relatively short expiration periods. Then, if a stream-cut is created for the stream during epochs ep2 or ep3, the stream-cut would have a short expiration time for segments s4 and s5. This would truncate segments s4 and s5 too soon using the stream-cut, which would be incorrect behavior, as stream data needs to be deleted in chronological order, and there are still events in segment s1 with an expiration time far in the future. Therefore, the system needs to retain data expiration information as the stream scales up and down and old segments get sealed.

Stream scale up/down events are controlled by the controller, which instructs the segment store to create new segments and seal old segments. The controller creates and maintains the predecessor-successor relationships between segments. For instance, segment s1 fromFIG.8Ais a predecessor segment of successor segments s4 and s5.

To retain the data expiration information, the controller has the successor segment(s) inherit the expiration times of their predecessor segment(s). During a scale-up operation, e.g., segment s1 is split into segment s4 and segment s5, the new segments inherit the final maximum expiration time of the predecessor segment as their initial maximum expiration times:
s4.initial_max_expiration_time=s1.final_max_expiration_time
s5.initial_max_expiration_time=s1.final_max_expiration_time

During scaling down, e.g., segments s2 and s3 are merged into segment s6, the successor segment inherits the maximal final maximum expiration time of the predecessor segments as its initial maximum expiration time:
s6.initial_max_expiration_time=max(s2.final_max_expiration_time,s3.final_max_expiration_time)

The inheriting of an expiration time by successor segment(s) makes the expiration task more straightforward to implement. If at least a part of some segment has expired, this means that all the predecessors of that segment have completely expired. The expiration task is free to delete such predecessors completely without additional precautions/pre-checks.

InFIG.8B, the shaded part of an active segment s11 (the topmost-rightmost one), has expired. That means that any predecessor segment(s) to s11, namely segments s1 and s9, have expired, as well as any predecessor segments of s1 and s9 (as well as their predecessor segment(s) and so on) have expired as well.

Because a stream's segments can be expired rather unevenly, the system checks to make sure there are no empty stream epochs. To this end, whenever the expiration task deletes a segment or its part, the expiration task looks for empty epochs and deletes them, if any. Note that this alternatively can be done in a separate task.

One or more aspects can be embodied in a system, such as represented inFIG.9, and for example can comprise a memory that stores computer executable components and/or operations, and a processor that executes computer executable components and/or operations stored in the memory. Example operations can comprise operation902, which represents associating a stream cut with a first segment of a data stream of events and with a second segment of the data stream of events. Operation904represents maintaining a first expiration time for the first segment, the first expiration time being defined based on a first greatest event expiration time of a first group of events appended to the first segment, the first segment comprising a first subgroup of events that are prior to the stream cut and currently expired based on the first expiration time. Operation906represents maintaining a second expiration time for the second segment, the second expiration time being defined based on a second greatest event expiration time of a second group of events appended to the second segment, the second segment comprising a second subgroup of events that are prior to the stream cut and are currently unexpired based on the second expiration time. Operation908represents deleting the first subgroup of events and retaining the second subgroup of events.

Further operations can comprise performing a scaling operation that splits the first segment into a third segment and a fourth segment, setting a third expiration time of the third segment to the first expiration time, and setting a fourth expiration time of the fourth segment to the first expiration time.

The stream cut can be a first stream cut, and further operations can comprise associating a second stream cut with the third segment and the fourth segment, determining that a third subgroup of events that are prior to the second stream cut are currently expired, deleting the third subgroup of events, and deleting the second segment.

Further operations can comprise deleting a predecessor segment of the second segment, the predecessor segment having been sealed in conjunction with the creation of the second segment in a scaling operation.

Further operations can comprise detecting an empty epoch having no associated segment, and deleting the empty epoch.

Further operations can comprise performing a scaling operation that merges the first segment and the second segment into a third segment, and setting a third expiration time of the third segment to the greater of the first expiration time or the second expiration time.

The stream cut can be a first stream cut, and further operations can comprise associating a second stream cut with the third segment, determining that a third subgroup of events that are prior to the second stream cut are currently expired, deleting the third subgroup of events, deleting the first segment and deleting the second segment.

Further operations can comprise deleting a predecessor segment of the first segment, the predecessor segment having been sealed in conjunction with the creation of the second segment in a scaling operation.

Further operations can comprise detecting an empty epoch having no associated segment, and deleting the empty epoch.

The first expiration time for the first segment can be maintained in first metadata of a first segment store instance associated with the first segment, and wherein the second expiration time for the second segment can be maintained in second metadata of a second segment store instance associated with the second segment.

One or more example aspects, such as corresponding to example operations of a method, are represented inFIG.10. Operation1002represents appending, by a streaming data storage system comprising a processor, an event to a segment of a data stream, the event associated with an event expiration time, and associated with a routing key by which the segment is determined. Operation1004represents obtaining, by the streaming data storage system, a stream cut expiration time associated with the segment and a stream cut. Operation1006represents determining, by the streaming data storage system, whether the event expiration time is greater than the stream cut expiration time associated with the segment. Operation1008represents in response to the event expiration time being determined to be greater than the stream cut expiration time associated with the segment, updating the stream cut expiration time to equal the event expiration time. Operation1010represents deleting, by the streaming data storage system, events from the segment that are prior to the stream cut and that are expired based on the stream cut expiration time.

Appending of the event to the segment and the updating of the stream cut expiration time to equal the event to equal the event expiration time can occur in an atomic operation.

The event can be a first event, wherein the segment can be a first segment, the event expiration time can be a first expiration time, the routing key can be a first routing key, and further operations can comprise appending, by the streaming data storage system, a second event to a second segment of the data stream, the second event associated with a second event expiration time, and associated with a second routing key by which the second segment is selected, obtaining, by the streaming data storage system, a second stream cut expiration time associated with the second segment and the stream cut, determining, by the streaming data storage system, whether the second event expiration time is greater than the second stream cut expiration time associated with the second segment, in response to the second event expiration time being determined to be greater than the second stream cut expiration time associated with the second segment, updating, by the streaming data storage system, the second stream cut expiration time to equal the second event expiration time, and deleting, by the streaming data storage system, events from the second segment that are prior to the stream cut and that are expired based on the second stream cut expiration time.

The segment can be a predecessor segment, and further operations can comprise detecting, by the streaming data storage system, a scaling event that creates successor segments from the predecessor segment and seals the predecessor segment, and initializing, by the streaming data storage system, the stream cut expiration time of each successor segment to the expiration time associated with the predecessor segment.

The segment can be a first predecessor segment, and further operations can comprise detecting, by the streaming data storage system, a scaling event that merges the first predecessor segment and a second predecessor segment into a successor segment, in response to the scaling event, obtaining, by the streaming data storage system, a maximum expiration time of the first predecessor segment and the second predecessor segment, and initializing, by the streaming data storage system, the stream cut expiration time of the successor segment to the maximum expiration time.

Further operations can comprise detecting, by the streaming data storage system, an empty epoch having no associated segment, and deleting the empty epoch.

FIG.11summarizes various example operations, e.g., corresponding to a machine-readable storage medium, comprising executable instructions that, when executed by a processor of a streaming data storage system, facilitate performance of operations. Operation1102represents appending events to active segments of a group of active segments associated with a data stream. Operation1104represents maintaining a segment identifier, expiration time grouping for each active segment, wherein the expiration time of each active segment is based on which event in the segment has a largest event expiration time. Operation1106represents writing a stream cut to an auxiliary stream cut segment associated with the data stream, the stream cut comprising the segment identifier, expiration time grouping for each active segment.

Further operations can comprise, for each segment of the group of active segments, accessing the stream cut to determine, based on the segment identifier, an expiration time grouping for the segment, whether the segment has expired events prior to the stream cut, and, in response to determining that the segment has expired events prior to the stream cut, deleting the expired events.

An active segment of the group can be a predecessor segment that is split into successor segments, and further operations can comprise, for each successor segment, initializing the segment identifier, expiration time grouping to the expiration time of the successor segment.

Two or more segments of the group can be predecessor segments that are merged into a successor segment, and further operations can comprise determining, based on the segment identifier, an expiration time grouping for each predecessor segment, a greatest expiration time among the two or more predecessor segments, and initializing a segment identifier, expiration time grouping of the successor segment to the greatest expiration time.

As can be seen, described herein is a technology that facilitates more flexible, fine-grained data expiration based on event-level expiration times in streaming data storage platforms/systems. The technology may be used to increase capacity use efficiency in streaming data storage platforms/systems.

FIG.12is a schematic block diagram of a computing environment1200with which the disclosed subject matter can interact. The system1200comprises one or more remote component(s)1210. The remote component(s)1210can be hardware and/or software (e.g., threads, processes, computing devices). In some embodiments, remote component(s)1210can be a distributed computer system, connected to a local automatic scaling component and/or programs that use the resources of a distributed computer system, via communication framework1240. Communication framework1240can comprise wired network devices, wireless network devices, mobile devices, wearable devices, radio access network devices, gateway devices, femtocell devices, servers, etc.

The system1200also comprises one or more local component(s)1220. The local component(s)1220can be hardware and/or software (e.g., threads, processes, computing devices). In some embodiments, local component(s)1220can comprise an automatic scaling component and/or programs that communicate/use the remote resources1210and1220, etc., connected to a remotely located distributed computing system via communication framework1240.

One possible communication between a remote component(s)1210and a local component(s)1220can be in the form of a data packet adapted to be transmitted between two or more computer processes. Another possible communication between a remote component(s)1210and a local component(s)1220can be in the form of circuit-switched data adapted to be transmitted between two or more computer processes in radio time slots. The system1200comprises a communication framework1240that can be employed to facilitate communications between the remote component(s)1210and the local component(s)1220, and can comprise an air interface, e.g., Uu interface of a UMTS network, via a long-term evolution (LTE) network, etc. Remote component(s)1210can be operably connected to one or more remote data store(s)1250, such as a hard drive, solid state drive, SIM card, device memory, etc., that can be employed to store information on the remote component(s)1210side of communication framework1240. Similarly, local component(s)1220can be operably connected to one or more local data store(s)1230, that can be employed to store information on the local component(s)1220side of communication framework1240.

With reference again toFIG.13, the example environment1300for implementing various embodiments of the aspects described herein includes a computer1302, the computer1302including a processing unit1304, a system memory1306and a system bus1308. The system bus1308couples system components including, but not limited to, the system memory1306to the processing unit1304. The processing unit1304can be any of various commercially available processors. Dual microprocessors and other multi-processor architectures can also be employed as the processing unit1304.

The system bus1308can be any of several types of bus structure that can further interconnect to a memory bus (with or without a memory controller), a peripheral bus, and a local bus using any of a variety of commercially available bus architectures. The system memory1306includes ROM1310and RAM1312. A basic input/output system (BIOS) can be stored in a non-volatile memory such as ROM, erasable programmable read only memory (EPROM), EEPROM, which BIOS contains the basic routines that help to transfer information between elements within the computer1302, such as during startup. The RAM1312can also include a high-speed RAM such as static RAM for caching data.

The computer1302further includes an internal hard disk drive (HDD)1314(e.g., EIDE, SATA), and can include one or more external storage devices1316(e.g., a magnetic floppy disk drive (FDD)1316, a memory stick or flash drive reader, a memory card reader, etc.). While the internal HDD1314is illustrated as located within the computer1302, the internal HDD1314can also be configured for external use in a suitable chassis (not shown). Additionally, while not shown in environment1300, a solid state drive (SSD) could be used in addition to, or in place of, an HDD1314.

Other internal or external storage can include at least one other storage device1320with storage media1322(e.g., a solid state storage device, a nonvolatile memory device, and/or an optical disk drive that can read or write from removable media such as a CD-ROM disc, a DVD, a BD, etc.). The external storage1316can be facilitated by a network virtual machine. The HDD1314, external storage device(s)1316and storage device (e.g., drive)1320can be connected to the system bus1308by an HDD interface1324, an external storage interface1326and a drive interface1328, respectively.

A number of program modules can be stored in the drives and RAM1312, including an operating system1330, one or more application programs1332, other program modules1334and program data1336. All or portions of the operating system, applications, modules, and/or data can also be cached in the RAM1312. The systems and methods described herein can be implemented utilizing various commercially available operating systems or combinations of operating systems.

Computer1302can optionally comprise emulation technologies. For example, a hypervisor (not shown) or other intermediary can emulate a hardware environment for operating system1330, and the emulated hardware can optionally be different from the hardware illustrated inFIG.13. In such an embodiment, operating system1330can comprise one virtual machine (VM) of multiple VMs hosted at computer1302. Furthermore, operating system1330can provide runtime environments, such as the Java runtime environment or the .NET framework, for applications1332. Runtime environments are consistent execution environments that allow applications1332to run on any operating system that includes the runtime environment. Similarly, operating system1330can support containers, and applications1332can be in the form of containers, which are lightweight, standalone, executable packages of software that include, e.g., code, runtime, system tools, system libraries and settings for an application.

A user can enter commands and information into the computer1302through one or more wired/wireless input devices, e.g., a keyboard1338, a touch screen1340, and a pointing device, such as a mouse1342. Other input devices (not shown) can include a microphone, an infrared (IR) remote control, a radio frequency (RF) remote control, or other remote control, a joystick, a virtual reality controller and/or virtual reality headset, a game pad, a stylus pen, an image input device, e.g., camera(s), a gesture sensor input device, a vision movement sensor input device, an emotion or facial detection device, a biometric input device, e.g., fingerprint or iris scanner, or the like. These and other input devices are often connected to the processing unit1304through an input device interface1344that can be coupled to the system bus1308, but can be connected by other interfaces, such as a parallel port, an IEEE 1394 serial port, a game port, a USB port, an IR interface, a BLUETOOTH® interface, etc.

A monitor1346or other type of display device can be also connected to the system bus1308via an interface, such as a video adapter1348. In addition to the monitor1346, a computer typically includes other peripheral output devices (not shown), such as speakers, printers, etc.

The computer1302can operate in a networked environment using logical connections via wired and/or wireless communications to one or more remote computers, such as a remote computer(s)1350. The remote computer(s)1350can be a workstation, a server computer, a router, a personal computer, portable computer, microprocessor-based entertainment appliance, a peer device or other common network node, and typically includes many or all of the elements described relative to the computer1302, although, for purposes of brevity, only a memory/storage device1352is illustrated. The logical connections depicted include wired/wireless connectivity to a local area network (LAN)1354and/or larger networks, e.g., a wide area network (WAN)1356. Such LAN and WAN networking environments are commonplace in offices and companies, and facilitate enterprise-wide computer networks, such as intranets, all of which can connect to a global communications network, e.g., the Internet.

When used in a LAN networking environment, the computer1302can be connected to the local network1354through a wired and/or wireless communication network interface or adapter1358. The adapter1358can facilitate wired or wireless communication to the LAN1354, which can also include a wireless access point (AP) disposed thereon for communicating with the adapter1358in a wireless mode.

When used in a WAN networking environment, the computer1302can include a modem1360or can be connected to a communications server on the WAN1356via other means for establishing communications over the WAN1356, such as by way of the Internet. The modem1360, which can be internal or external and a wired or wireless device, can be connected to the system bus1308via the input device interface1344. In a networked environment, program modules depicted relative to the computer1302or portions thereof, can be stored in the remote memory/storage device1352. It will be appreciated that the network connections shown are example and other means of establishing a communications link between the computers can be used.

When used in either a LAN or WAN networking environment, the computer1302can access cloud storage systems or other network-based storage systems in addition to, or in place of, external storage devices1316as described above. Generally, a connection between the computer1302and a cloud storage system can be established over a LAN1354or WAN1356e.g., by the adapter1358or modem1360, respectively. Upon connecting the computer1302to an associated cloud storage system, the external storage interface1326can, with the aid of the adapter1358and/or modem1360, manage storage provided by the cloud storage system as it would other types of external storage. For instance, the external storage interface1326can be configured to provide access to cloud storage sources as if those sources were physically connected to the computer1302.