Type safe Histograms

Merge pull request #48 from smrutilal2/fix-build

upgrade dependencies with known vulnerabilities in undertow-httphandler

publish to sonatype repo

Merge pull request #44 from smrutilal2/fix-pom-description

fix the pom description

Substitute `NULL` for missing tag values in reporters.

If a tag value is null in the tags array, the literal string NULL will now be substituted. If a null tag key or a null metric string (or null field for Influx) is found, the reporter will log and skip those entries instead of throwing a NullPointerException.

GC optimization

Java's for each loop is a big source of garbage. Every time it records a value, it creates an instance of ArrayList Iterator. The release addressed the issue by using the traditional index based for loop instead.

Fix Issue #29 - Copy Tags by Value

ConcurrentMonoid Tables were copying references to Tags array passed in. This caused a bug whenever the caller tried to modify the array in order to minimize garbage on their end. To make matters worse, the pattern encouraged caller to produce more garbage by making a new array for each call, or to maintain a cache themselves in a thread-safe manner.

This release fixes the problem by copying Tags array by value. While this might sounds like a memory concern, the copy only happens on first occurrence for a given metric, and encourages a cleaner pattern for caller.

0.4.0

Merge pull request #20 from smrutilal2/enrich

Configurable max cardinality per metric

Histograms

Merge pull request #7 from smrutilal2/histograms

Base histogram implementation

Initial Release

Validating pipelines.