Blank ID indicates something has gone wrong, maybe in delta generation.
If there are many nodes with blank ID then the mapping stage consumes
lots of CPU, so eliminate the possibility when results are collected.
These can be long-running operations, and if the client retries we get
the cancelled one running in parallel with the retry, slowing both down
and making it likely the next one will time out too.
These can be long-running operations, and if the client retries we get
the cancelled one running in parallel with the retry, slowing both down
and making it likely the next one will time out too.
Typically this means the http caller has closed the connection,
so no point responding to them.
Also check at the point we send a response back, and log to OpenTracing.
The only place Counters are used is in rendering, for the number of
nodes under a topology, so the overhead of holding a unique data
structure in every Node is unwarranted.
Counters are not set in the probe, so we don't need any
backwards-compatibility in report decoding. Similarly they are not set
until after all nodes are merged, so we don't need that logic.
* Pass Go context down to Renderers
This is useful for cancellation or tracing.
* Add tracing spans to app
Also log things like number of nodes in Map, total number of reports.
joinResults grew out of a special case of Map.Render(), so now we
merge the two lines back together and have just one way to accumulate
results and remap adjacencies.
After dropping extra metadata in the rest of this PR, our usage of
joinResults.add* only ever ends creating minimal nodes, from just an
id and topology. Hence joinResults.add* can be invoked with simply an
id and topology instead of a generic node creation function.
Any existing list would be mutated by result(), which is bad.
Note that all the existing newJoinResults() call sites pass in nodes
with no adjacencies, so this is purely a safety measure.
This is preparatory to future refactorings: all existing calls are to
Endpoints which have no children and where we don't want a Counter.
We make addChildAndChildren an obvious extension of addChild even
though it adds a dead code path (we never call addChildAndChildren
with an endpoint).
Decoration is in fact quite a simple process that is applied on entry
to rendering: we take a base renderer, transform it with a decorator,
and then render a report with it. The new render.Decorate() function
does exactly that.
There is one exception. When rendering an individual node, e.g. for
showing its details panel in the UI, we must not lose the node during
decoration. That requires some special logic, which previously resided
in the PreciousNodeRenderer, and now lives in handleNode.
Squash of:
* We have to keep all the container hostnames until the end so we can
count how many we've filtered
* Adding tests for ContainerHostnameRenderer and PodServiceRenderer with
filters
* Because we filter on image name we need the image name before
filtering
* Alternative approach to passing decorators.
* Refactor out some of the decorator capture
* Don't memoise decorated calls to Render
* Fixing filtered counts on containers topology
Tricky, because we need the filters to be silent sometimes (when they're
in the middle), but not when they're at the top, so we take the "top"
filter's stats. However, this means we have to compose all
user-specified filters into a single Filter layer, so we can get all
stats.
There are no more Silent filters, as all filters are silent (unless they
are at the top).
Additionally, I clarified some of the filters as their usage/terminology
was inconsistent and confused. Now Filter(IsFoo, ...) *keeps* only nodes
where IsFoo is true.
Squash of:
- use detailed.Summaries to render topology nodes
- ban merging nodes of different topologies (they should be mapped)
- need to prune parents when mapping node types
- render container images by id if they have no name
- remove separate render ids and prune parents in NewDerived*
- don't render metrics/metadata for groups of nodes
- fixing up tests
- removing pending unit tests (for mapping.go, for now)
- updating experimental dir for RenderableNode removal
