zipkin.storage

Class InMemorySpanStore

java.lang.Object

zipkin.storage.InMemorySpanStore

All Implemented Interfaces:

SpanStore

public final class InMemorySpanStore
extends Object
implements SpanStore

Internally, spans are indexed on 64-bit trace ID

Here's an example of some traces in memory:

 spansByTraceIdTimeStamp:
    <aaaa,July 4> --> ( spanA(time:July 4, traceId:aaaa, service:foo, name:GET),
                        spanB(time:July 4, traceId:aaaa, service:bar, name:GET) )
    <cccc,July 4> --> ( spanC(time:July 4, traceId:aaaa, service:foo, name:GET) )
    <bbbb,July 5> --> ( spanD(time:July 5, traceId:bbbb, service:biz, name:GET) )
    <bbbb,July 6> --> ( spanE(time:July 6, traceId:bbbb) service:foo, name:POST )

 traceIdToTraceIdTimeStamps:
    aaaa --> [ <aaaa,July 4> ]
    bbbb --> [ <bbbb,July 5>, <bbbb,July 6> ]
    cccc --> [ <cccc,July 4> ]

 serviceToTraceIds:
    foo --> [ <aaaa>, <cccc>, <bbbb> ]
    bar --> [ <aaaa> ]
    biz --> [ <bbbb> ]

 serviceToSpanNames:
    bar --> ( GET )
    biz --> ( GET )
    foo --> ( GET, POST )
 

Constructor Summary

Constructors

Constructor and Description
InMemorySpanStore()

Method Summary

Modifier and Type	Method and Description
List<DependencyLink>	getDependencies(long endTs, Long lookback) Returns dependency links derived from spans.
List<Span>	getRawTrace(long traceId) This calls SpanStore.getRawTrace(long, long) with traceIdHigh set to zero.
List<Span>	getRawTrace(long traceIdHigh, long traceId) Retrieves spans that share a 128-bit trace id, as returned from backend data store queries, with no ordering expectation.
List<List<Span>>	getRawTraces() Used for testing.
List<String>	getServiceNames() Get all the service names.
List<String>	getSpanNames(String service) Get all the span names for a particular Endpoint.serviceName.
List<Span>	getTrace(long traceId) This calls SpanStore.getTrace(long, long) with traceIdHigh set to zero.
List<Span>	getTrace(long traceIdHigh, long traceIdLow) Get the available trace information from the storage system.
List<List<Span>>	getTraces(QueryRequest request) Get the available trace information from the storage system.
List<Long>	traceIds() Deprecated. use getRawTraces()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

InMemorySpanStore

public InMemorySpanStore()

Method Detail

traceIds

@Deprecated
public List<Long> traceIds()

Deprecated. use getRawTraces()

getRawTraces

public List<List<Span>> getRawTraces()

Used for testing. Returns all traces unconditionally.

getTraces

public List<List<Span>> getTraces(QueryRequest request)

Description copied from interface: SpanStore

Get the available trace information from the storage system. Spans in trace are sorted by the first annotation timestamp in that span. First event should be first in the spans list.

Results are sorted in order of the first span's timestamp, and contain up to QueryRequest.limit elements.

If StorageComponent.Builder.strictTraceId(boolean) is enabled, spans with the same 64-bit trace ID will be grouped together.

Specified by:

getTraces in interface SpanStore

getTrace

public List<Span> getTrace(long traceId)

Description copied from interface: SpanStore

This calls SpanStore.getTrace(long, long) with traceIdHigh set to zero.

Specified by:

getTrace in interface SpanStore

getTrace

public List<Span> getTrace(long traceIdHigh,
                           long traceIdLow)

Description copied from interface: SpanStore

Get the available trace information from the storage system. Spans in trace are sorted by the first annotation timestamp in that span. First event should be first in the spans list.

When StorageComponent.Builder.strictTraceId(boolean) is true, spans with the same traceIdLow are returned even if the traceIdHigh is different.

Specified by:

getTrace in interface SpanStore

Parameters:

traceIdHigh - The upper 64-bits of the trace ID. See Span.traceIdHigh

traceIdLow - The lower 64-bits of the trace ID. See Span.traceId

Returns:

a list of spans with the same 128-bit trace ID, or null if not present.

getRawTrace

public List<Span> getRawTrace(long traceId)

Description copied from interface: SpanStore

This calls SpanStore.getRawTrace(long, long) with traceIdHigh set to zero.

Specified by:

getRawTrace in interface SpanStore

getRawTrace

public List<Span> getRawTrace(long traceIdHigh,
                              long traceId)

Description copied from interface: SpanStore

Retrieves spans that share a 128-bit trace id, as returned from backend data store queries, with no ordering expectation.

This is different, but related to SpanStore.getTrace(long, long). SpanStore.getTrace(long, long) cleans data by merging spans, adding timestamps and performing clock skew adjustment. This feature is for debugging zipkin logic or zipkin instrumentation.

When StorageComponent.Builder.strictTraceId(boolean) is true, spans with the same traceIdLow are returned even if the traceIdHigh is different.

Specified by:

getRawTrace in interface SpanStore

Parameters:

traceIdHigh - The upper 64-bits of the trace ID. See Span.traceIdHigh

traceId - The lower 64-bits of the trace ID. See Span.traceId

Returns:

a list of spans with the same 128-bit trace ID, or null if not present.

getServiceNames

public List<String> getServiceNames()

Description copied from interface: SpanStore

Get all the service names.

Results are sorted lexicographically

Specified by:

getServiceNames in interface SpanStore

getSpanNames

public List<String> getSpanNames(String service)

Description copied from interface: SpanStore

Get all the span names for a particular Endpoint.serviceName.

Results are sorted lexicographically

Specified by:

getSpanNames in interface SpanStore

getDependencies

public List<DependencyLink> getDependencies(long endTs,
                                            @Nullable
                                            Long lookback)

Description copied from interface: SpanStore

Returns dependency links derived from spans.

Implementations may bucket aggregated data, for example daily. When this is the case, endTs may be floored to align with that bucket, for example midnight if daily. lookback applies to the original endTs, even when bucketed. Using the daily example, if endTs was 11pm and lookback was 25 hours, the implementation would query against 2 buckets.

Some implementations parse Span from storage and call DependencyLinker to aggregate links. The reason is certain graph logic, such as skipping up the tree is difficult to implement as a storage query.

There's no parameter to indicate how to handle mixed ID length: this operates the same as if StorageComponent.Builder.strictTraceId(boolean) was set to false. This ensures call counts are not incremented twice due to one hop downgrading from 128 to 64-bit trace IDs.

Specified by:

getDependencies in interface SpanStore

Parameters:

endTs - only return links from spans where Span.timestamp are at or before this time in epoch milliseconds.

lookback - only return links from spans where Span.timestamp are at or after (endTs - lookback) in milliseconds. Defaults to endTs.

Returns:

dependency links in an interval contained by (endTs - lookback) or empty if none are found