Tests showed that importing a single line with 70MB size takes 5.3GiB
RSS memory for VictoriaMetrics single-node.
In the scenario when user exports and imports data from one VM to another,
it could possibly lead to OOM exception for destination VM.
Importing a single line with 16MB size taks 1.3GiB RSS memory.
Hence, the limit for `import.maxLineLen` was decreased from 100MB to 10MB
to improve reliability of VictoriaMetrics during imports.
Signed-off-by: hagen1778 <roman@victoriametrics.com>
Co-authored-by: Aliaksandr Valialkin <valyala@victoriametrics.com>
Previously bytesutil.Resize() was copying the original byte slice contents to a newly allocated slice.
This wasted CPU cycles and memory bandwidth in some places, where the original slice contents wasn't needed
after slize resizing. Switch such places to bytesutil.ResizeNoCopy().
Rename the original bytesutil.Resize() function to bytesutil.ResizeWithCopy() for the sake of improved readability.
Additionally, allocate new slice with `make()` instead of `append()`. This guarantees that the capacity of the allocated slice
exactly matches the requested size. The `append()` could return a slice with bigger capacity as an optimization for further `append()` calls.
This could result in excess memory usage when the returned byte slice was cached (for instance, in lib/blockcache).
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/2007
