This commit adds support for replacing regexes with non-regex conditions
when possible. Currently the following regexes are supported:
- host =~ /^foo$/ will be converted into host = 'foo'
- host !~ /^foo$/ will be converted into host != 'foo'
Note: if the regex expression contains character classes, grouping,
repetition or similar, it may not be rewritten.
For example, the condition: name =~ /^foo|bar$/ will not be rewritten.
Support for this may arrive in the future.
Regexes that can be converted into simpler expression will be able to
take advantage of the tsdb index, making them significantly faster.
Previously, calling derivative with a non-duration second argument was
allowed during parsing but would panic during execution due to a failed
type conversion. This change ensures the second argument is a duration
literal.
The functionality works the same as wildcards, but this time, you can
specify a regular expression.
One limitation is that you can't specify whether you only want to select
fields or tags. Since the regex can be changed to suit the person's
needs, I don't currently think this is an issue.
Strings would always return an empty string and stddev is meaningless
when it comes to strings. This removes that functionality so strings
don't automatically get picked up when using a wildcard.
The `cumulative_sum()` function can be used to sum each new point and
output the current total. For the following points:
cpu value=2 0
cpu value=4 10
cpu value=6 20
This would output the following points:
> SELECT cumulative_sum(value) FROM cpu
time value
---- -----
0 2
10 6
20 12
As can be seen, each new point adds to the sum of the previous point and
outputs the value with the same timestamp.
The function can also be used with an aggregate like `derivative()`.
> SELECT cumulative_sum(mean(value) FROM cpu WHERE time >= now() - 10m GROUP BY time(1m)
First Pass at implementing sample
Add sample iterators for all types
Remove size from sample struct
Fix off by one error when generating random number
Add benchmarks for sample iterator
Add test and associated fixes for off by one error
Add test for sample function
Remove NumericLiteral from sample function call
Make clear that the counter is incr w/ each call
Rename IsRandom to AllSamplesSeen
Add a rng for each reducer that is created
The default rng that comes with math/rand has a global lock. To avoid
having to worry about any contention on the lock, each reducer now has
its own time seeded rng.
Add sample function to changelog
Clean up template for fill average
Change fill(average) to fill(linear)
Update average to linear in infuxql spec
Add Integer Tests and associated fixes
Update CHANGELOG for fill(linear)
Manual use of system queries could result in a user using the query
incorrect. Rather than check to make sure the query was used correctly,
we're just going to prevent users from using those sources so they can't
use them incorrectly.
The vet checks for some files did not pass for go 1.7. As part of a
preliminary start to making go 1.7 work with this software, go vet
should pass.
Also updated the gogo/protobuf dependency which fixed the code generator
to work with go 1.7 too. Ran `go generate` on the entire repository to
ensure every file was up to date.
The derivative() call would panic if it received two points at the same
time because it tried to divide by zero. The derivative call now skips
past these points. To avoid skipping past these points, use `GROUP BY *`
so that each series is kept separated into their own series.
The difference() call has also been modified to skip past these points.
Even though difference doesn't divide by the time, difference is
supposed to perform the same as derivative, but without dividing by the
time.
Return an error when we encounter the same option twice in ALTER
RETENTION POLICY and remove the `maxNumOptions` number from the parsing
loop. The `maxNumOptions` number would need to be modified if another
option was added to the parsing loop and it didn't correctly prevent
duplicate options from being reported as an error anyway.
Normalize all of the SHOW commands so they allow both using ON to
specify the database and using the default database. Some commands would
require one and some would require the other and it was confusing when
using the query language.
Affected commands:
* SHOW RETENTION POLICIES
* SHOW MEASUREMENTS
* SHOW SERIES
* SHOW TAG KEYS
* SHOW TAG VALUES
* SHOW FIELD KEYS
When attempting to reduce the WHERE clause, the time literals had not
been converted from string literals yet. This adds the functionality to
have it handle the same time math when the time literal is still a
string literal.
The dollar sign would sometimes be accepted as whitespace if it was
immediately followed by a reserved keyword or an invalid character. It
now reads these properly as a bound parameter rather than ignoring the
dollar sign.
Instead of having the parser set the defaults, the command will set the
defaults so that the constants for that are actually used. This way we
can also identify which things the user provided and which ones we are
filling with default values.
This allows the meta client to be able to make smarter decisions when
determining if the user requested a conflict or if the requested
capabilities match with what is currently available. If you just say
`CREATE DATABASE WITH NAME myrp`, the user doesn't really care what the
duration of the retention policy is and just wants to use the default.
Now, we can use that information to determine if an existing retention
policy would conflict with what the user requested rather than returning
an error if a default value ever gets changed since the meta client
command can communicate intent more easily.
We added `SHARD DURATION` as an extra option, but forgot to increase the
maximum number of allowable options from 3 to 4. So if 4 options were
used, the last one was ignored. This was commonly `DEFAULT`, but it
could have been any of the options.
Negative timestamps are now supported. We also now refuse two
nanoseconds that are at the edge of the minimum time window. One of the
nanoseconds we do not accept is because we need MinInt64 to be used for
some internal comparisons in the TSM engine and it was causing an
underflow when we subtracted one from the minimum time. The second is so
we can have one minimum time that signifies the default minimum that
nobody can write to (so we can implicitly rewrite the timestamp on
aggregate queries) but still use the explicit timestamp if it is given
to us by the user. We aren't able to tell the difference between if the
user provided it or if it was implicit without those values being
different.
If the default minimum time is used with an aggregate query, we rewrite
the time to be the epoch for backwards compatibility since we believe
that's more important than supporting that extra nanosecond.
This allows a long series of uninterruptible statements to still be
interrupted for a long running query that might do something like create
or drop many databases.
It is now possible to use a mixed duration unit like `1h30m`. The
duration units can be in whatever order as long as they are connected to
each other.
There is a change to the scanner. A token such as `10x` will be scanned
as a duration literal, but will then fail to parse as an invalid
duration. This should not be a breaking change as there is no situation
where `10m10` was a valid order of tokens for the parser.
Fixes#3634.
The query executor would only store the number of active queries and the
query duration so it was impossible to determine how many queries were
actually executed during that timeframe because quick queries would be
gone before the call to gather statistics was made.
This adds two new statistics so track when queries start and when
queries finish and doesn't decrement the counter so the number of
executed queries can be obtained using `derivative()` and
`difference()`.
Instead of having the parser set the defaults, the command will set the
defaults so that the constants for that are actually used. This way we
can also identify which things the user provided and which ones we are
filling with default values.
This allows the meta client to be able to make smarter decisions when
determining if the user requested a conflict or if the requested
capabilities match with what is currently available. If you just say
`CREATE DATABASE WITH NAME myrp`, the user doesn't really care what the
duration of the retention policy is and just wants to use the default.
Now, we can use that information to determine if an existing retention
policy would conflict with what the user requested rather than returning
an error if a default value ever gets changed since the meta client
command can communicate intent more easily.
This commit fixes the `MaxSelectSeriesN` limit which was broken by
the implementation of lazy iterators. The setting previously limited
the total number of series but the new implementation limits the
concurrent number of series being processed.
This commit limits queries to only process one shard at a time.
However, within a shard, multiple series can still be processed in
parallel. Shard iterators are lazily instantiated during query
execution to limit the amount of memory a given query uses.
The previous parseFill would try to parse an expression and only unscan
one token when it failed. This caused it to not put back the correct
number of tokens with some expression.
Now it has been modified to check for the fill ident ahead of time and
then use ParseExpr() to parse the call. If the expression fails to parse
into a call, it will send an error instead of trying to continue with an
invalid parser state.
Fixes#6543.
The `SHOW MEASUREMENTS` and `SHOW TAG VALUES` cannot go through the
query engine to get the speed they need. They also only need access to
the database index and do not need access to specific shards. This
removes the query rewriting that was done to turn these two queries into
a select statement and reimplements them inside of the coordinator as an
interface on the TSDBStore.
Truncate the time interval output of the monitor service to be on even
time intervals rather than on every minute based on the start time. This
normalizes the output from the monitor service.
Previously, it encoded the text representation of the regex literal
which included the surrounding slashes used in the query language. The
binary encoding should only include the exact string used to create the
regular expression.
The tsdb package had a substantial amount of dead code related to the
old query engine still in there. It is no longer used, so it was removed
since it was left unmaintained. There is likely still more code that is
the same, but wasn't found as part of this code cleanup.
influxql has dead code show up because of the code generation so it is
not included in this pruning.
The highest time represented by a nanosecond needs to be used for an
exclusive range, so the maximum time needs to be one less than the
possible maximum number of nanoseconds representable by an int64 so that
we don't lose a point at that one time.
Previously worked in the open source version because the timestamp used
for finding a shard would be truncated by the retention policy so the
lookup time didn't run into this edge case because it didn't rest on the
truncation boundary. Since that point didn't really belong in that shard
group and was placed there by mistake, it's best to fix this bug since
the timestamp used to create the shard group should be capable of
retrieving it.
This adds support for using regex expressions in SHOW TAG VALUES when
selecting the key. Also supporting the `!=` operation for the
comparison. Now you can do any of the following:
SHOW TAG VALUES WITH KEY != "region"
SHOW TAG VALUES WITH KEY =~ /region/
SHOW TAG VALUES WITH KEY !~ /region/
It also adds a new SetLiteral AST node that will potentially be used in
the future to allow set operations for other comparisons in the future.
Fixes#4532.
The task manager now acts as its own statement executor so that a custom
statement executor can perform custom actions for KillQueryStatement and
ShowQueriesStatement.
This allows us to add additional options to ExecuteQuery without
creating parameter bloat.
Removing the unused Series structs. Their necessity was removed by a
previous commit, but the structs were not removed yet.
Add another type of interrupt iterator that monitors the interrupt
channel and calls `Close()` on the iterator when the interrupt happens.
It will primarily be used for asynchronously closing the ReaderIterator,
but it will only close the read side of the connection properly. More
work needs to be done to allow closing the write side efficiently.
The current code would compare every string literal it crossed and tried
to coerce them to time literals if the _looked_ like date/time strings.
The only time the TimeLiteral was used is when comparing to the the
'time' value in a where clause. This change moves the string parsing
code until we attempt to compare 'time' to a string, at which point we
know we need/want a TimeLiteral, and not just an ordinary string.
Fixes#6727
The default retention policy name is changed to "autogen" instead of
"default" since it ends up being ambiguous when we tell a user to check
the default retention policy, it is uncertain if we are referring to the
default retention policy (which can be changed) or the retention policy
with the name "default".
Now the automatically generated retention policy name is "autogen".
The default retention policy is now also configurable through the
configuration file so an administrator can customize what they think
should be the default.
Fixes#3733.
A query's String method is called multiple times per query. This commit
ensures all calls to query.String share use of a strings.NewReplacer.
This approximately halves the number of allocations for the benchmarked
query.
If you use a statement like this:
SELECT value FROM one..cpu, two..cpu
It will access both the `one` and `two` databases as if you had selected
the `cpu` measurement twice for both of them. Updated the `tsdb.Shard`
create iterator function to filter out any sources that do not apply to
that shard so this duplication doesn't happen.
Fixes#6701.
The parser can be passed a map of keys to literal values to be replaced
into the query. Parameters are preceded by a dollar sign (`$`). If a
parameter key is missing, an error is thrown by the parser.
Fixes#2926.
Casting syntax is done with the PostgreSQL syntax `field1::float` to
specify which type should be used when selecting a field. You can also
do `field1::field` or `tag1::tag` to specify that a field or tag should
be selected.
This makes it possible to select a tag when a field key and a tag key
conflict with each other in a measurement. It also means it's possible
to choose a field with a specific type if multiple shards disagree. If
no types are given, the same ordering for how a type is chosen is used
to determine which type to return.
The FieldDimensions method has been updated to return the data type for
the fields that get returned. The SeriesKeys function has also been
removed since it is no longer needed. SeriesKeys was originally used for
the fill iterator, but then expanded to be used by auxiliary iterators
for determining the channel iterator types. The fill iterator doesn't
need it anymore and the auxiliary types are better served by
FieldDimensions implementing that functionality, so SeriesKeys is no
longer needed.
Fixes#6519.
encodeTags would encode the tags by outputting every key followed by
every value in alphabetical order. decodeTags would try to read this in
an old format that printed tags in key/value order.
This fix matches decodeTags to match the same format encodeTags outputs.
This commit moves the `CallIterator` to wrap the individual series
instead of wrapping a shard. This allows individual points to be
aggregated before being merged.
This will cause a small increase in memory usuage per series but
it shows a 20% decrease in query time when there are a moderate
number of points per series.
This commit changes the `SeriesIterator` to process one measurement
at a time and uses a `floatFastDedupeIterator` to avoid point
encoding during deduplication.
If a shard is empty for a specific field and the field type is something
other than a float, a nil iterator would get returned from one of the
empty shards and cause the combined iterators to be cast to the float
type and all other iterator types to be discarded (or for integers, to
be cast).
This is rare since most aggregates don't accept strings or booleans, but
for queries like:
SELECT distinct(string) FROM mydata
It would result in nothing getting returned if one of the shards didn't
have a value for `string`.
This change modifies the query engine to return nil for the shards
instead of a fake iterator and then to only use the fake iterator if the
final aggregate iterator is nil (meaning that no iterators could be
constructed for the field from any shard).
Fixes#6495.
An offset of `time(1m, now())` will anchor the offset to the current
time of the query. The default offset is `0s` which is the current
default anyway.
This fixes#2074 by making time zone offset support unnecessary. Time
comparisons can use timezones inside of the time clause and the offset
needed for non-hour timezone differences can be used as part of the
offset argument.
Also removes the functions `HasSimpleCount()` and `HasCountDistinct()`
as they are no longer useful. They had a small role in validation that
has now been moved into `validateAggregates()`.
Fixes#6472.
The time of the point will be returned with a selector when there is no
group by interval and when there is only one selector. Any other
conditions will return the start time of the interval.
Fixes#5890.
In order to follow REST a bit more carefully, all write operations
should go through a POST in the future. We still allow read operations
through either GET or POST (similar to the Graphite /render endpoint),
but write operations will trigger a returned warning as part of the JSON
response and will eventually return an error.
Also updates the Golang client libraries to always use POST instead of
GET.
Fixes#6290.
The interrupt iterator currently introduces a non-trivial amount of
overhead to queries by checking for interrupts every 256 points.
This commit adjusts that check to every 5000 points.
There are also several places where nested field access has been
adjusted to minimize field lookups.
This commit removes support for `SHOW SERVERS` and `DROP SERVER`
from the `influxql` package. It also removes extraneous cluster
testing code from `cmd/influxd/run`.
Fixes#6465
The derivative function had an arbitrary limitation that would cause it
to set the value to zero if the previous value was after the next value.
This caused all `ORDER BY desc` queries with `derivative()` to always
return zero values.
Fixes#4675.
Sanitizing is now done through pattern matching rather than parsing the
query and replacing the password in the query. This prevents
accidentally redacting the wrong part of a query and revealing what the
password is through association.
Fixes#3883.
This removes the previous restrictions that kept derivative as only
capable of being used in a single field and only at the top level.
This lets users determine how they want to use derivative more freely
and opens up the possibility of also using math between derivatives.
This may open up some problems when it comes to math between derivatives
as timestamps may not match correctly. That is likely a problem related
to any binary math to begin with though and can probably be ignored by
the derivatives. I'm also not sure it makes sense to perform any math
between a derivative and a difference or perform math between a
derivative and a mean.
Fixes#6118.
This has various benefits:
- Users embedding InfluxDB within other Go programs can specify a different logger / prefix easily.
- More consistent with code used elsewhere in InfluxDB (e.g. services, other `run.Server.*` fields, etc).
- This is also more efficient, because it means `executeQuery` no longer allocates a single `*log.Logger` each time it is called.
The series keys within a tag set were previously not sorted which would
cause the output to be non-deterministic. This sorts the output series
by their keys so it has a consistent output especially when using
limits.
Fixes#3166.
This also switches the remaining iterators to be lazy so they can return
errors properly. They needed to be converted to lazy initialization
anyway, which has the side effect of making it much easier for us to
propagate the underlying error during initialization.
Updated the Emitter to return errors when it cannot read properly from
the iterators.
The optional sections of the command consumed the semicolon token and
didn't put it back for the outer loop. The code shouldn't explicitly
check for a semicolon or EOF anyway, so these checks were removed and
the token gets unscanned if it doesn't match the optional token that the
parser is looking for.
Fixes#6398.
For aggregate queries, derivatives will now alter the start time to one
interval behind and will use that interval to find the derivative of the
first point instead of giving no value for that interval. Null values
will still be discarded so if the interval before the one you are
querying is null, then it will be discarded like if it were in the
middle of the query. You can use `fill(0)` to fill in these values.
This does not apply to raw queries yet.
Also modified the derivative and difference aggregates to use the stream
iterator instead of the reduce slice iterator for space efficiency.
Fixes#3247. Contributes to #5943.
The deprecated message is now attached to a new attribute returned with
the results. This message can then be read by clients to warn a user
about upcoming changes to the query engine.
The `influx` client has already been modified to read this message and
print it out for every format except CSV.
The first warning message is a deprecated message about removing `IF NOT
EXISTS` from `CREATE DATABASE`.
The message will also be printed to the server log.
Fixes#5707.
This commit changes the channel iterators to use a double buffer
to reduce allocations. The caller of `Iterator.Next()` must copy
out the point before calling `Next()` again.
The `percentile()` call previously did not validate that the first
argument was a variable reference and that would let an invalid query
slip by that would panic the query engine.
Added checking for this case and also included test cases for the other
calls that require a variable reference as the first argument.
Fixes#6379.
Change distinct so it uses a custom reducer that keeps internal state
instead of requiring all of the points to be kept as a slice in memory.
Fixes#6261.
This commit makes a number of performance improvements to
reduce allocations during query execution. Several objects
and buffers are now reused across the components to avoid
allocations.
Previously a simple `count(value)` query across 1M points
would require 26,000+ allocations. After the changes in
this commit that number has been reduced to 88.
If a point had no tags at all and was asked for the subset of tags with
at least one key, it would return a new set of tags that was completely
empty. In contrast, if the point had any tags at all, it would return a
set of tags with the tag value being an empty string. This lead to
a point with no tags being treated differently than a point with at
least one tag.
Fixing this so the tag value will always be an empty string for
consistency. A missing tag should always be empty.
The following query was fixed previously:
SELECT 'value' FROM cpu
This ended up hitting the `buildExprIterator()` code path and was
handled properly. But this query:
SELECT 'value', value FROM cpu
This took a different code path that would trigger a panic because it
triggered a panic instead of an error condition. This code path has now
been modified to trigger an error instead of a panic.
Fixes#6248.
Fixes#6211.
In Go-land packages with the same name, e.g., internal, do not clash
with each other when they're in different parts of the project. However
with protobufs definitions will clash if they share the same package
name.
This commit renames the influxql protobuf package to `influxql` to
avoid a clash with a message definition in another protobuf package
called internal. Go package aliases allow us to continue to refer to the
internal package as `internal` rather than `influxql`.
The QueryExecutor had a lot of dead code made obsolete by the query
engine refactor that has now been removed. The TSDBStore interface has
also been cleaned up so we can have multiple implementations of this
(such as a local and remote version).
A StatementExecutor interface has been created for adding custom
functionality to the QueryExecutor that may not be available in the open
source version. The QueryExecutor delegate all statement execution to
the StatementExecutor and the QueryExecutor will only keep track of
housekeeping. Implementing additional queries is as simple as wrapping
the cluster.StatementExecutor struct or replacing it with something
completely different.
The PointsWriter in the QueryExecutor has been changed to a simple
interface that implements the one method needed by the query executor.
This is to allow different PointsWriter implementations to be used by
the QueryExecutor. It has also been moved into the StatementExecutor
instead.
The TSDBStore interface has now been modified to contain the code for
creating an IteratorCreator. This is so the underlying TSDBStore can
implement different ways of accessing the underlying shards rather than
always having to access each shard individually (such as batch
requests).
Remove the show servers handling. This isn't a valid command in the open
source version of InfluxDB anymore.
The QueryManager interface is now built into QueryExecutor and is no
longer necessary. The StatementExecutor and QueryExecutor split allows
task management to much more easily be built into QueryExecutor rather
than as a separate struct.
A bigger refactor of these functions is needed to support #3290, but
this will work for the more common case that someone uses double quotes
instead of single quotes when surrounding a time literal.
Fixes#3932.
This commit sets the `MergeIterator.init` flag after initialization.
Previously this would generate a new heap on every call to `Next()`
which caused some aggregate queries to slow by ~10,000%.
The MergeIterator creation function would call `peek()` on the iterator
to initialize the heap. Since this function can sometimes take a long
time (such as a huge aggregate query on a shard), the
`influxql.Select()` wouldn't return until the query had already been
completed.
The `influxql.Select()` call should be just the creation of the
iterators and shouldn't calculate anything. This is important for future
features like the point limiter that have to be initialized after the
`influxql.Select()` call.
The simple moving average will gradually emit points instead of waiting
until the end. This should apply to derivative and difference in the
future too.
Fixes#6112.
Related to #6140, but won't actually fix that problem. It will correctly
stop new queries from being started during shutdown and will send the
interrupt signal to queries during shutdown.
Since the interrupt signal is asynchronous, there isn't currently a way
to wait for the queries to complete themselves before shutting down the
engine.
The difference function is implemented very similar to how derivative is
implemented. It is an aggregate function that acts over the entire
aggregate. This function will also have the same problems that
derivative has with getting values from the previous interval or point.
This will be fixed separately as part of #5943.
Fixes#1825.
Allows configuration of shard group duration at database creation, and retention
policy create/alter time.
Query examples:
```
CREATE DATABASE testdb WITH DURATION 90d SHARD DURATION 30m NAME rp_testdb
CREATE RETENTION POLICY rp_testdb2 ON testdb DURATION INF REPLICATION 1 SHARD DURATION 30m
ALTER RETENTION POLICY rp_testdb2 ON testdb SHARD DURATION 1h
```
This can be useful with long duration retention policies with lots of data, where
you can split into smaller shards to relieve memory pressure.
This allows multiple semicolons in a row now and also requires that a
semicolon separate commands. The query specification says this is
required, but a boolean error in `ParseQuery` makes one semicolon
optional and multiple semicolons an error.
Fixes#5728.
This commit adds an `IteratorStats` that holds aggregate
iterator processing information. A method is also added to
`Iterator` to return the stats:
Stats() influxql.IteratorStats
The remote iterators will also emit their stats in the point
stream upon first connection, on a given interval, and then
finally once the last point has been sent.
Use of the iterator is spread out into both `IteratorCreators` and
inside of the iterators themselves. Part of the interrupt must be
handled inside of the engine so it stops trying to emit points when an
interrupt is found and another part of the interrupt has to happen when
combining the iterators so it doesn't just start reading the next shard.
While this allows a query to be killed, it doesn't really do anything
yet since the interrupt happens only after the first row gets emitted
(the entire first series).
This section of code will likely have to be refactored to make this work
since we need a way to interrupt a currently running iterator.
The currently running queries can be listed with the command
`SHOW QUERIES` and it will display the current commands that have been
run, the database they were run against, and how long they have been
running.
Numbers in the query without any decimal will now be emitted as integers
instead and be parsed as an IntegerLiteral. This ensures we keep the
original context that a query was issued with and allows us to act more
similar to how programming languages are typically structured when it
comes to floats and ints.
This adds functionality for dealing with integers promoting to floats in
the various different places where math are used.
Fixes#5744 and #5629.
Normalize the time for the distinct() call to either be at the beginning
of the group by interval or the start time similar to every other call.
The timestamp previously just showed the first time found and didn't
make a lot of sense in the context of what the function was supposed to
do.
Fixes#6040.
Internal system series start with an underscore prefix but
restricting this prevents users who already use an underscore
prefix in their series names.
Fixes#5870
This commit moves the `tsdb.Store.ExpandSources()` function onto
the `influxql.IteratorCreator` and provides support for issuing
source expansion across a cluster.
Now the AuxIterator will know when it is backgrounded so that it can
stop reading from the primary iterator when all of the child iterators
have been closed.
This commit moves the `tsdb.Store.ExpandSources()` function onto
the `influxql.IteratorCreator` and provides support for issuing
source expansion across a cluster.
The primary input iterator for an aux iterator would continue trying to
send points to a closed channel even after an aux iterator had already
been closed.
This changes the aux iterators to use sync.Cond instead of channels and
lower level syncing primitives for handling buffered input/output.
Fixes#5974.
Also fixes derivative calls with an aggregate function to require a
group by interval. The call without a group by interval doesn't make
sense as it will never return anything since it will always have one
point.
Fixes#5968.
`SHOW TAG VALUES` output has been modified to print the measurement name
for every measurement and to return the output in two columns: key and
value. An example output might be:
> SHOW TAG VALUES WITH KEY IN (host, region)
name: cpu
---------
key value
host server01
region useast
name: mem
---------
key value
host server02
region useast
`measurementsByExpr` has been taught how to handle reserved keys (ones
with an underscore at the beginning) to allow reusing that function and
skipping over expressions that don't matter to the call.
Fixes#5593.
Previously the call iterator would normalize the time to the interval
for all calls. This meant that when `first()` or `last()` was called
with no group by interval the value would be found for each shard, the
time was normalized, then it tried to find the value between the shards
(but no longer with any time data as that had already been eliminated).
This removes part of the time logic from the call iterators and makes a
new iterator `IntervalIterator` to normalize the times as they come out
of the underlying iterator.
Fixes#5890.
All three of these iterators are supposed to support all four types of
iterators, but the implementation was never done for string or boolean.
Fixes#5886.
This refactor is primarily to support Kapacitor. Kapacitor doesn't care
about the iterators and mostly keeps the points it handles in memory.
The iterator interface is more than Kapacitor cares about.
This commit refactors and opens up the internals of aggregating and
reducing incoming points so it can be used by an outside library with
the same code. It also makes the iterators used by the call iterators
publically usable with new functionality.
Reducers are split into two methods which are separate interfaces that
can be combined for dealing with casting between different types. The
Aggregator interfaces accept points into the aggregator and retain any
internal state they need. The Emitter interface will then create a point
from that aggregated state which can be fed to the iterator. The
Emitters do not fill in the name or tag of the point as that is expected
to be done by the person aggregating the point. While the Emitters do
sometimes fill in the time, that value will also be overwritten by the
iterator. Filling in the time is to allow a future version that will
allow returning the point time instead of just the interval time.
The limit iterator would short circuit if there were no dimensions and
all points had been read. It also needs to consider that multiple
sources will require reading the entire iterator too, so the short
circuit requires only a single source.
Fixes#5871.
The RPC handler for remote queries would attempt to reuse a closed
connection for certain commands that didn't use pooling. The RPC
commands that close the connection have been fixed to not try reusing
the connection.
When creating an iterator, if there are no points to return, the points
decoder would hit an EOF that it didn't catch and would return that
error back to the client who made the request. It now properly returns
no points by using a `nilFloatIterator` if there are no points to
return.
This fixes remote execution when a cluster has nothing to return.
The dimensions array in `RewriteWildcards` gets emptied by an earlier
section of the code and then tries to iterate over that empty slice to
append it to the list of dimensions.
That makes the loop dead code that can't ever be hit.
Also improve the efficiency of this method by not creating a new slice
when there are no wildcards. We already check at the beginning of the
function if there is a wildcard out of necessity. There's no point in
making a new slice and copying the contents if we know that there will
be no wildcards to expand.
It also improves memory efficiency by assuming that if a wildcard
exists, there is only one and the pre-allocated slice can take advantage
of that. If there are multiple wildcards, then a new slice will have to
be created in the middle of the loop to raise the capacity.
When a wildcard is specified for the field but not the dimensions, the
dimensions get added to the list of fields as part of
`RewriteWildcards()`.
But when a dimension was given with no wildcard, the dimension didn't
get removed from the wildcard in the fields section. This teaches the
rewriter to disclude dimensions explicitly included from being expanded
as a field. Now this statement when a measurement has one tag named host
and a field named value:
SELECT * FROM cpu GROUP BY host
Would expand to this:
SELECT value FROM cpu GROUP BY host
Instead of this:
SELECT host, value FROM cpu GROUP BY host
If you want the latter behavior, you can include it like this:
SELECT host, * FROM cpu GROUP BY host
Fixes#5770.
Edd Robinson
Jonathan A. Sternberg
Mark Rushakoff
Michael Desa
Jason Wilder
Cory LaNou
Nathaniel Cook
Nathaniel Cook
Ashish Gaurav
Ben Johnson
Joe LeGasse
David Norton
lvheyang
Stephen Gutekanst
thbourlove
Jonathan A. Sternberg
Tait Clarridge