The skeleton of the two existing scylla-native tools (scylla-types and
scylla-sstable) is very similar. By skeleton, I mean all the boilerplate
around creating and configuring a seastar::app_template, representing
operations/command and their options, and presenting and selecting
these.
To facilitate code-sharing and quick development of any new tools,
extract this skeleton from scylla-sstable.cc into tools/utils.hh,
in the form of a new tool_app_template, which wraps a
seastar::app_template and centralizes all the boilerplate logic in a
single place. The extracted code is not a simple copy-paste, although
many elements are simply copied. The original code is not removed yet.
Use the new seastar option to instruct seastar to not initialize and use
the seastar allocator, relying on the standard allocator instead.
Configure LSA with the standard allocator based segment store backend:
* scylla-types reserves 1MB for LSA -- in theory nothing here should use
LSA, but just in case...
* scylla-sstable reserves 100MB for LSA, to avoid excessive trashing in
the sstable index caches.
With this, tools now should allocate memory on demand, without reserving
a large chunk of (or all of) the available memory, as regular seastar
apps do.
Instead of lengthy blurbs, switch to single-line, machine-readable
standardized (https://spdx.dev) license identifiers. The Linux kernel
switched long ago, so there is strong precedent.
Three cases are handled: AGPL-only, Apache-only, and dual licensed.
For the latter case, I chose (AGPL-3.0-or-later and Apache-2.0),
reasoning that our changes are extensive enough to apply our license.
The changes we applied mechanically with a script, except to
licenses/README.md.
Closes#9937
Which configures seastar to act more appropriate to a tool app. I.e.
don't act as if it owns the place, taking over all system resources.
These tools are often run on a developer machine, or even next to a
running scylla instance, we want them to be the least intrusive
possible.
Also use the new tool mode in the existing tools.
Signed-off-by: Botond Dénes <bdenes@scylladb.com>
Message-Id: <20211220143104.132327-1-bdenes@scylladb.com>
