+ 1 from my side 1) it is well known mature profiling tool, there are other cases when Apache projects embedded it, for example: - https://issues.apache.org/jira/browse/HADOOP-18055 - https://issues.apache.org/jira/browse/HBASE-29045 - https://issues.apache.org/jira/browse/FLINK-33325 2) Apache-2.0 license 3) the dependency has a small size (less than 1Mb) and does not have transitive dependencies to other 3rd parties 4) the main contributors are now in Amazon, it is even included into Corretto JDK now ( https://aws.amazon.com/about-aws/whats-new/2025/10/amazon-corretto-october-2025-quarterly-updates/ ) 5) the logic is disabled by default, so no impact if you do not use it.
On Wed, 10 Dec 2025 at 18:08, Štefan Miklošovič <[email protected]> wrote: > This capability is disabled by default, it is driven by a system > property you have to set to true in order to be able to get an > instance of AsyncProfiler which does the actual profiling. If > disabled, which is default, then any calls via nodetool which needs > AsyncProfiler (start, stop, status) would return a message that > profiling is not enabled. > > Not sure if this answers your concerns but without knowingly turning > it on nothing happens. > > On Wed, Dec 10, 2025 at 6:28 PM David Capwell <[email protected]> wrote: > > > > I have no issues adding it. I think my only real comment would be the > same as with manager; w/e we expose to the public api (in this case > Nodetool) we have to support, so if a 3rd party lib breaks compatibility > that puts us in a bind if we didn’t think about that up front. > > > > Having async-profiler exposed makes it easier to profile is a good > thing. Manager has (or is in the process of adding) API auth so we can > lock down async-profiler to those “allowed” but do we have similar in > Nodetool? We had an issue in the past that async-profiler would trigger a > JVM crash (JVM bug), so we had to limit calls to it until it was fixed. > > > > > On Dec 10, 2025, at 9:00 AM, Štefan Miklošovič <[email protected]> > wrote: > > > > > > Worth to mention that we were also contemplating about the inclusion > > > of jfr-convert so a user can also convert raw JFR files to e.g. HTML > > > with heatmaps but we evaluated that it is not necessary. Sure, it > > > would be comfortable, but ultimately not needed. Conversion of such a > > > file via nodetool, on server side, is just not a good idea, it is not > > > a job of a server to convert anything. > > > > > > In majority of cases, people using the profiler just want to get a > > > HTML with cpu / allocation profile, it can even gather JFR files as > > > such and fetch it is, it is just that the conversion as such can > > > happen on client's side instead. > > > > > > I am +1 for introducing the core async profiler library only. > > > > > > On Wed, Dec 10, 2025 at 5:46 PM Bernardo Botella > > > <[email protected]> wrote: > > >> > > >> Hi everyone! > > >> > > >> I’d like to propose adding the async-profiler library to the > Cassandra project. This will enable us to add a new nodetool command to do > profiling tasks on the process running Cassandra. This information can be > useful to debug a wide range of potential issues and performance > optimizations. CASSANDRA-20854 captures the effort and the details of the > proposal, and this PR proposes its implementation. > > >> > > >> I want to note that this feature was already discussed in this > thread, and this one only want to make sure that no one has any concerns > about adding the library as a dependency. > > >> > > >> What is async-profiler? > > >> async-profiler is a low overhead sampling profiler for Java that does > not suffer from the Safepoint bias problem. It features HotSpot-specific > API to collect stack traces and to track memory allocations. The profiler > works with OpenJDK and other Java runtimes based on the HotSpot JVM. > > >> > > >> Unlike traditional Java profilers, async-profiler monitors non-Java > threads (e.g., GC and JIT compiler threads) and shows native and kernel > frames in stack traces. > > >> > > >> What can be profiled: > > >> > > >> CPU time > > >> Allocations in Java Heap > > >> Native memory allocations and leaks > > >> Contended locks > > >> Hardware and software performance counters like cache misses, page > faults, context switches > > >> and more. > > >> > > >> > > >> We propose to add async-profiler 4.2 as a dependency to Cassandra. > > >> > > >> Any concerns? > > >> Bernardo > > > -- Dmitry Konstantinov
