Currently, rendering a view is capable of handling multiple ops for
the same fingerprint efficiently. However, this capability requires a
lot of complexity in the code, which we are not using at all because
the way we assemble a viewRequest will never have more than one
operation per fingerprint.
This commit weeds out the said capability, along with all the code
needed for it. It is still possible to have more than one operation
for the same fingerprint, it will just be handled in a less efficient
way (as proven by the unit tests).
As a result, scanjob.go could be removed entirely.
This commit also contains a few related refactorings and removals of
dead code in operation.go, view,go, and freelist.go. Also, the
docstrings received some love.
Change-Id: I032b976e0880151c3f3fdb3234fb65e484f0e2e5
We have seven different types all called like LevelDB.*Options. One
of them is the plain LevelDBOptions. All others are just wrapping that
type without adding anything except clunkier handling.
If there ever was a plan to add more specific options to the various
LevelDB.*Options types, history has proven that nothing like that is
going to happen anytime soon.
To keep the code a bit shorter and more focused on the real (quite
significant) complexities we have to deal with here, this commit
reduces all uses of LevelDBOptions to the actual LevelDBOptions type.
1576 fewer characters to read...
Change-Id: I3d7a2b7ffed78b337aa37f812c53c058329ecaa6
- Mostly docstring fixed/additions.
(Please review these carefully, since most of them were missing, I
had to guess them from an outsider's perspective. (Which on the
other hand proves how desperately required many of these docstrings
are.))
- Removed all uses of new(...) to meet our own style guide (draft).
- Fixed all other 'go vet' and 'golint' issues (except those that are
not fixable (i.e. caused by bugs in or by design of 'go vet' and
'golint')).
- Some trivial refactorings, like reorder functions, minor renames, ...
- Some slightly less trivial refactoring, mostly to reduce code
duplication by embedding types instead of writing many explicit
forwarders.
- Cleaned up the interface structure a bit. (Most significant probably
the removal of the View-like methods from MetricPersistenc. Now they
are only in View and not duplicated anymore.)
- Removed dead code. (Probably not all of it, but it's a first
step...)
- Fixed a leftover in storage/metric/end_to_end_test.go (that made
some parts of the code never execute (incidentally, those parts
were broken (and I fixed them, too))).
Change-Id: Ibcac069940d118a88f783314f5b4595dce6641d5
Mostly, that means adding compliant doc strings to exported items.
Also, remove 'go vet' warnings where possible. (Some are unfortunately
not to avoid, arguably bugs in 'go vet'.)
Change-Id: I2827b6dd317492864c1383c3de1ea9eac5a219bb
This way the binary will be built in a clear environment and prometheus
can be added to the docker index.
Change-Id: I417fb90adf2503c990a96f4bad370b09b102e0b9
So far, we are compiling C/C++ code without any optimization.
In non-representative, but practically relevant tests, the -O3
improved the total query time for a demanding graph by ~20%.
Change-Id: I5e8123650e53a4933ed4fbe63d0b1ca67217b865
Problem description:
====================
If a rule evaluation referencing a metric/timeseries M happens at a time
when M doesn't have a memory timeseries yet, looking up the fingerprint
for M (via TieredStorage.GetMetricForFingerprint()) will create a new
Metric object for M which gets both: a) attached to a new empty memory
timeseries (so we don't have to ask disk for the Metric's fingerprint
next time), and b) returned to the rule evaluation layer. However, the
rule evaluation layer replaces the name label (and possibly other
labels) of the metric with the name of the recorded rule. Since both
the rule evaluator and the memory storage share a reference to the same
Metric object, the original memory timeseries will now also be
incorrectly renamed.
Fix:
====
Instead of storing a reference to a shared metric object, take a copy of
the object when creating an empty memory timeseries for caching
purposes.
Change-Id: I9f2172696c16c10b377e6708553a46ef29390f1e
The storage itself should be closed before any of the objects passed into it
are closed (otherwise closing the storage can randomly freeze). Defers are
executed in reverse order, so closing the storage should be the last of the
defer statements.
Change-Id: Id920318b876f5b94767ed48c81221b3456770620
This used to work with Go 1.1, but only because of a compiler bug.
The bug is fixed in Go 1.2, so we have to fix our code now.
Change-Id: I5a9f3a15878afd750e848be33e90b05f3aa055e1
Prometheus needs long-term storage. Since we don't have enough resources
to build our own timeseries storage from scratch ontop of Riak,
Cassandra or a similar distributed datastore at the moment, we're
planning on using OpenTSDB as long-term storage for Prometheus. It's
data model is roughly compatible with that of Prometheus, with some
caveats.
As a first step, this adds write-only replication from Prometheus to
OpenTSDB, with the following things worth noting:
1)
I tried to keep the integration lightweight, meaning that anything
related to OpenTSDB is isolated to its own package and only main knows
about it (essentially it tees all samples to both the existing storage
and TSDB). It's not touching the existing TieredStorage at all to avoid
more complexity in that area. This might change in the future,
especially if we decide to implement a read path for OpenTSDB through
Prometheus as well.
2)
Backpressure while sending to OpenTSDB is handled by simply dropping
samples on the floor when the in-memory queue of samples destined for
OpenTSDB runs full. Prometheus also only attempts to send samples once,
rather than implementing a complex retry algorithm. Thus, replication to
OpenTSDB is best-effort for now. If needed, this may be extended in the
future.
3)
Samples are sent in batches of limited size to OpenTSDB. The optimal
batch size, timeout parameters, etc. may need to be adjusted in the
future.
4)
OpenTSDB has different rules for legal characters in tag (label) values.
While Prometheus allows any characters in label values, OpenTSDB limits
them to a to z, A to Z, 0 to 9, -, _, . and /. Currently any illegal
characters in Prometheus label values are simply replaced by an
underscore. Especially when integrating OpenTSDB with the read path in
Prometheus, we'll need to reconsider this: either we'll need to
introduce the same limitations for Prometheus labels or escape/encode
illegal characters in OpenTSDB in such a way that they are fully
decodable again when reading through Prometheus, so that corresponding
timeseries in both systems match in their labelsets.
Change-Id: I8394c9c55dbac3946a0fa497f566d5e6e2d600b5
MIN/MAX/SUM/AVG/COUNT aggregations will now by default drop all labels that are
not specifically part of a BY-clause, even if a label value is the same within
all timeseries of an aggregation group. The old behavior of keeping extra
labels may still be switched on by adding KEEPING_EXTRA to the end of an
aggregation statement:
sum(http_requests) by (job, method) keeping_extra
I'm open to better syntax/naming suggestions.
Change-Id: I21d3fe7af9e98552ce3dffa3ce7c0a4ba4c0b4a4
