In Alternator's HTTP API, response headers can dominate bandwidth for
small payloads. The Server, Date, and Content-Type headers were sent on
every response but many clients never use them.
This patch introduces three Alternator config options:
- alternator_http_response_server_header,
- alternator_http_response_disable_date_header,
- alternator_http_response_disable_content_type_header,
which allow customizing or suppressing the respective HTTP response
headers. All three options support live update (no restart needed).
The Server header is no longer sent by default; the Date and
Content-Type defaults preserve the existing behavior.
The Server and Date header suppression uses Seastar's
set_server_header() and set_generate_date_header() APIs added in
https://github.com/scylladb/seastar/pull/3217. This patch also
fixes deprecation warnings from older Seastar HTTP APIs.
Tests are in test/alternator/test_http_headers.py.
Fixes https://scylladb.atlassian.net/browse/SCYLLADB-70Closesscylladb/scylladb#28288
This patch adds to the existing collection of tests for Alternator
response compression another test with a tiny response being compressed.
This test serves two purposes:
1. It verifies setting alternator_response_compression_threshold_in_bytes
to a tiny number like 1 really means that tiny responses would be
compressed.
2. It verifies that our compression code, which has a special code path
for the small chunk at the end of the compression, works correctly.
The original motivation for writing this test was a false alarm by
Claude Code which claimed that Alternator's response compression code
has a serious, exploitable, memory overrun bug, because it set the
wrong size limit on that last chunk. Claude was wrong, there is no such
bug. We did set an oversized limit on the last chunk (so this patch
fixes this typo), but it didn't matter - because the code used
deflateBound - the guaranteed maximum size of the uncompressed data -
for the buffer's size, so the buffer was unconditionally big enough,
no matter which avail_out limit we passed to delate() it could never
overflow.
The included test passes even before this patch, even with ASAN
enabled to detect memory overflows - no overflow was happening.
It also passes after the typo correction in this patch.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Closesscylladb/scylladb#29718
In Alternator's HTTP API, response headers can dominate bandwidth for
small payloads. The Server, Date, and Content-Type headers were sent on
every response but many clients never use them.
This patch introduces three Alternator config options:
- alternator_http_response_server_header,
- alternator_http_response_disable_date_header,
- alternator_http_response_disable_content_type_header,
which allow customizing or suppressing the respective HTTP response
headers. All three options support live update (no restart needed).
The Server header is no longer sent by default; the Date and
Content-Type defaults preserve the existing behavior.
The Server and Date header suppression uses Seastar's
set_server_header() and set_generate_date_header() APIs added in
https://github.com/scylladb/seastar/pull/3217. This patch also
fixes deprecation warnings from older Seastar HTTP APIs.
Tests are in test/alternator/test_http_headers.py.
Fixes https://scylladb.atlassian.net/browse/SCYLLADB-70Closesscylladb/scylladb#28288
This patch continues the effort to split the huge executor.cc (5000
lines before this patch) even more.
In this patch we introduce a new source file, executor_util.cc, for
various utility functions that are used for many different operations
and therefore are useful to have in a header file. These utility
functions will now be in executor_util.cc and executor_util.hh -
instead of executor.cc and executor.hh.
Various source files, including executor.cc, the executor_read.cc
introduced in the previous patch, as well as older source files like
as streams.cc, ttl.cc and serialization.cc, use the new header file.
This patch removes over 700 lines of code from executor.cc, and
also removes a large amount of utility functions declerations from
executor.hh. Originally, executor.hh was meant to be about the
interface that the Alternator server needs to *execute* the different
DynamoDB API operations - and after this patch it returns closer to
this original goal.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Previous commit added means to decide whether client asks for compression and with which algorithm.
This patch adds actual compression of responses based on zlib library.
For now only string (not chunked) responses are compressed.
Several previously defined tests start to pass.
This is an initial patch to add support of Alternator's compressed responses.
The actual compression (gzip,deflate) will be added in the following commits.
The main functionality added in this commmit is parsing of Accept-Encoding header,
that indicates compression algorithms supported by the client.
In this commit we add also configuration parameters of response gzip/deflate compression.
They allow to enable/disable compression, set level and a size threshold below which a response is not compressed.
With current implementation it is possible to decide a compression for each response, but it is not used yet.
