We do not know which fields exist at compile time.
But it is a great help to have some pre-selected
fields in groupBy.
Solved by adding a configuration option.
When using autocomplete to return field values I
missed, that autocomplete had the feature that cut
values at dots. So instead of returning full field
values only the prefix up to the first dot was
returned.
Fixed by making the cut-at-dot feature optional.
We had a method that returned the values of a field
with respect to a query. That method was inefficient,
because it executed the query, fetched all Docs
and collected the values.
The autocomplete method we introduced a while back
can answer the same question but much more efficiently.
People are having trouble to understand durations like
100000 or 2.7E+6 milliseconds. Therefore we are
hanging the labels on the y-axis to include the unit
in the tic's label. We also use multiples of seconds,
minutes, hours and days instead of multiples of 10.
In order to prevent files from getting too big and
make it easier to implement retention policies, we
are splitting all files into chunks. Each chunk
contains the data for a time interval (1 month per
default).
This first changeset introduces the ClusteredPersistentMap
that implements this for PersistentMap. It is used
for a couple (not all) of indices.
Due to a mistake in Tag which added all strings used
by Tag into the String dictionary, the dictionary
did contain all values that were used in queries.
We are now reading the CSV input without transforming
the data into strings. This reduces the amount of bytes
that have to be converted and copied.
We also made Tag smaller. It no longer stores pointers
to strings, instead it stored integers obtained by
compressing the strings (see StringCompressor). This
reduces memory usage and it speeds up hashcode and
equals, which speeds up access to the writer cache.
Performance gain is almost 100%:
- 330k entries/s -> 670k entries/s, top speed measured over a second
- 62s -> 32s, to ingest 16 million entries
One bottleneck was the blocking queue used to transport entries
from the listener thread to the ingestor thread.
Reduced the bottleneck by batching entries.
Interestingly the batch size of 100 was better than batch size
of 1000 and better than 10.
I was finally able to show that there is a tiny but measureable
effect of this buffer. I think it was not visible before,
because the parsing was too slow. But now, that I replaced the
date parser, the ingestion thread is twice as fast as the
insertion thread. Therefore the buffer makes more sense.
Compared to FastISODateParser.parse, which returns an
OffsetDateTime object, parseAsEpochMilli returns the
epoch time millis. The performance improvement for
date parsing alone is roughly 100% (8m dates/s to
18m dates/s).
Insertion speed improved from 13-14s for 1.6m entries
to 11.5-12.5s.
A specialized date parser that can only handle ISO-8601 like dates
(2011-12-03T10:15:30.123Z or 2011-12-03T10:15:30+01:00) but does this
roughly 10 times faster than DateTimeFormatter and 5 times
faster than the FastDateParser of commons-lang3.
- PdbFiles no longer require dates to be monotonically
increasing. Therefore TagsToFile does not have to ensure
this. => We only have one file per Tags.
- Use EhCache instead of HashMap.
- The DiskStorage uses only one file instead of millions.
Also the block size is only 512 byte instead of 4kb, which
helps to reduce the memory usage for short sequences.
- Update primitiveCollections to get the new LongList.range
and LongList.rangeClosed methods.
- BSFile now stores Time&Value sequences and knows how to
encode the time values with delta encoding.
- Doc had to do some magic tricks to save memory. The path
was initialized lazy and stored as byte array. This is no
longer necessary. The patch was replaced by the
rootBlockNumber of the BSFile.
- Had to temporarily disable the 'in' queries.
- The stored values are now processed as stream of LongLists
instead of Entry. The overhead for creating Entries is
gone, so is the memory overhead, because Entry was an
object and had a reference to the tags, which is
unnecessary.
