e71e1dc964
Introduce a new "script" operation, which loads a script from the specified path, then feeds the mutation fragment stream to it. The script can then extract, process and present information from the sstable as it wishes.
For now only Lua scripts are supported for the simple reason that Lua is easy to write bindings for, it is simple and lightweight and more importantly we already have Lua included in the Scylla binary as it is used as the implementation language for UDF/UDA. We might consider WASM support in the future, but for now we don't have any language support in WASM available.
Example:
```lua
function new_stats(key)
return {
partition_key = key,
total = 0,
partition = 0,
static_row = 0,
clustering_row = 0,
range_tombstone_change = 0,
};
end
total_stats = new_stats(nil);
function inc_stat(stats, field)
stats[field] = stats[field] + 1;
stats.total = stats.total + 1;
total_stats[field] = total_stats[field] + 1;
total_stats.total = total_stats.total + 1;
end
function on_new_sstable(sst)
max_partition_stats = new_stats(nil);
if sst then
current_sst_filename = sst.filename;
else
current_sst_filename = nil;
end
end
function consume_partition_start(ps)
current_partition_stats = new_stats(ps.key);
inc_stat(current_partition_stats, "partition");
end
function consume_static_row(sr)
inc_stat(current_partition_stats, "static_row");
end
function consume_clustering_row(cr)
inc_stat(current_partition_stats, "clustering_row");
end
function consume_range_tombstone_change(crt)
inc_stat(current_partition_stats, "range_tombstone_change");
end
function consume_partition_end()
if current_partition_stats.total > max_partition_stats.total then
max_partition_stats = current_partition_stats;
end
end
function on_end_of_sstable()
if current_sst_filename then
print(string.format("Stats for sstable %s:", current_sst_filename));
else
print("Stats for stream:");
end
print(string.format("\t%d fragments in %d partitions - %d static rows, %d clustering rows and %d range tombstone changes",
total_stats.total,
total_stats.partition,
total_stats.static_row,
total_stats.clustering_row,
total_stats.range_tombstone_change));
print(string.format("\tPartition with max number of fragments (%d): %s - %d static rows, %d clustering rows and %d range tombstone changes",
max_partition_stats.total,
max_partition_stats.partition_key,
max_partition_stats.static_row,
max_partition_stats.clustering_row,
max_partition_stats.range_tombstone_change));
end
```
Running this script wilt yield the following:
```
$ scylla sstable script --script-file fragment-stats.lua --system-schema system_schema.columns /var/lib/scylla/data/system_schema/columns-24101c25a2ae3af787c1b40ee1aca33f/me-1-big-Data.db
Stats for sstable /var/lib/scylla/data/system_schema/columns-24101c25a2ae3af787c1b40ee1aca33f//me-1-big-Data.db:
397 fragments in 7 partitions - 0 static rows, 362 clustering rows and 28 range tombstone changes
Partition with max number of fragments (180): system - 0 static rows, 179 clustering rows and 0 range tombstone changes
```
Fixes: https://github.com/scylladb/scylladb/issues/9679
Closes #11649
* github.com:scylladb/scylladb:
tools/scylla-sstable: consume_reader(): improve pause heuristincs
test/cql-pytest/test_tools.py: add test for scylla-sstable script
tools: add scylla-sstable-scripts directory
tools/scylla-sstable: remove custom operation
tools/scylla-sstable: add script operation
tools/sstable: introduce the Lua sstable consumer
dht/i_partitioner.hh: ring_position_ext: add weight() accessor
lang/lua: export Scylla <-> lua type conversion methods
lang/lua: use correct lib name for string lib
lang/lua: fix type in aligned_used_data (meant to be user_data)
lang/lua: use lua_State* in Scylla type <-> Lua type conversions
tools/sstable_consumer: more consistent method naming
tools/scylla-sstable: extract sstable_consumer interface into own header
tools/json_writer: add accessor to underlying writer
tools/scylla-sstable: fix indentation
tools/scylla-sstable: export mutation_fragment_json_writer declaration
tools/scylla-sstable: mutation_fragment_json_writer un-implement sstable_consumer
tools/scylla-sstable: extract json writing logic from json_dumper
tools/scylla-sstable: extract json_writer into its own header
tools/scylla-sstable: use json_writer::DataKey() to write all keys
tools/scylla-types: fix use-after-free on main lambda captures
ScyllaDB Documentation
This repository contains the source files for ScyllaDB Open Source documentation.
- The
devfolder contains developer-oriented documentation related to the ScyllaDB code base. It is not published and is only available via GitHub. - All other folders and files contain user-oriented documentation related to ScyllaDB Open Source and are sources for docs.scylladb.com.
To report a documentation bug or suggest an improvement, open an issue in GitHub issues for this project.
To contribute to the documentation, open a GitHub pull request.
Key Guidelines for Contributors
- Follow the ScyllaDB Style Guide.
- The user documentation is written in reStructuredText (RST) - a plaintext markup language similar to Markdown. If you're not familiar with RST, see ScyllaDB RST Examples.
- The developer documentation is written in Markdown. See Basic Markdown Syntax for reference.
Creating Knowledge Base Articles
The kb/ directory holds source files for knowledge base articles in the Knowledge Base section of the ScyllaDB documentation.
The kb/kb_common subdirectory contains a template for knowledge base articles to help you create new articles.
To create a new knowledge base article (KB):
- Copy the
kb-article-template.rstfile from/kb/kb_commonto/kband rename it with a unique name. - Open the new file and fill in the required information.
- Remove what is not needed.
- Run
make previewto build the docs and preview them locally. - Send a PR with "KB" in its title.
Building User Documentation
Prerequisites
- Python 3. Check your version with
$ python --version. - poetry 1.12 or later
- make
Mac OS X
You must have a working Homebrew in order to install the needed tools.
You also need the standard utility make.
Check if you have these two items with the following commands:
brew help
make -h
Linux Distributions
Building the user docs should work out of the box on most Linux distributions.
Windows
Use "Bash on Ubuntu on Windows" for the same tools and capabilities as on Linux distributions.
Building the Docs
- Run
make previewto build the documentation. - Preview the built documentation locally at http://127.0.0.1:5500/.
Cleanup
You can clean up all the build products and auto-installed Python stuff with:
make pristine
Information for Contributors
If you are interested in contributing to Scylla docs, please read the Scylla open source page at http://www.scylladb.com/opensource/ and complete a Scylla contributor agreement if needed. We can only accept documentation pull requests if we have a contributor agreement on file for you.
Third-party Documentation
-
Do any copying as a separate commit. Always commit an unmodified version first and then do any editing in a separate commit.
-
We already have a copy of the Apache license in our tree, so you do not need to commit a copy of the license.
-
Include the copyright header from the source file in the edited version. If you are copying an Apache Cassandra document with no copyright header, use:
This document includes material from Apache Cassandra.
Apache Cassandra is Copyright 2009-2014 The Apache Software Foundation.