Before these changes, we didn't specify which I/O scheduling
group commitlog instances in hinted handoff should use.
In this commit, we set it explicitly to the commitlog
scheduling group. The rationale for this choice is the fact
we don't want to cause a bottleneck on the write path
-- if hints are written too slowly, new incoming mutations
(NOT hints) might be rejected due to a too high number
of hints currently being written to disk; see
`storage_proxy::create_write_response_handler_helper()`
for more context.
(cherry picked from commit 6a7fb18b52)
Closesscylladb/scylladb#20094
This pull request introduces host ID in the Hinted Handoff module. Nodes are now identified by their host IDs instead of their IPs. The conversion occurs on the boundary between the module and `storage_proxy.hh`, but aside from that, IPs have been erased.
The changes take into considerations that there might still be old hints, still identified by IPs, on disk – at start-up, we map them to host IDs if it's possible so that they're not lost.
Refs scylladb/scylladb#6403Fixesscylladb/scylladb#12278Closesscylladb/scylladb#15567
* github.com:scylladb/scylladb:
docs: Update Hinted Handoff documentation
db/hints: Add endpoint_downtime_not_bigger_than()
db/hints: Migrate hinted handoff when cluster feature is enabled
db/hints: Handle arbitrary directories in resource manager
db/hints: Start using hint_directory_manager
db/hints: Enforce providing IP in get_ep_manager()
db/hints: Introduce hint_directory_manager
db/hints/resource_manager: Update function description
db/hints: Coroutinize space_watchdog::scan_one_ep_dir()
db/hints: Expose update lock of space watchdog
db/hints: Add function for migrating hint directories to host ID
db/hints: Take both IP and host ID when storing hints
db/hints: Prepare initializing endpoint managers for migrating from IP to host ID
db/hints: Migrate to locator::host_id
db/hints: Remove noexcept in do_send_one_mutation()
service: Add locator::host_id to on_leave_cluster
service: Fix indentation
db/hints: Fix indentation
This commit introduces a new class responsible
for keeping track of mappings IP-host ID.
Before hinted handoff is migrated to using
host IDs, hint directories still have to
represent IP addresses. However, since
we identify endpoint managers by host IDs
already, we need to be able to associate
them with the directories they manage.
This class serves this purpose.
We extract the initialization of endpoint managers
from the start method of the hint manager
to a separate function and make it handle directories
that represent either IP addresses, or host IDs;
other directories are ignored.
It's necessary because before Scylla is upgraded
to a version that uses host-ID-based hinted handoff,
we need to continue only managing IP directories.
When Scylla has been upgraded, we will need to handle
host ID directories.
It may also happen that after an upgrade (but not
before it), Scylla fails while renaming
the directories, so we end up with some of them
representing IP address, and some representing
host IDs. After these changes, the code handles
that scenario as well.
We change the type of node identifiers
used within the module and fix compilation.
Directories storing hints to specific nodes
are now represented by host IDs instead of
IPs.
While the function is marked as noexcept, the returned
future can in fact store an exception. We remove the
specifier to reflect the actual behavior of the
function.
before this change, we rely on the default-generated fmt::formatter
created from operator<<, but fmt v10 dropped the default-generated
formatter.
in this change, we include `fmt/ranges.h` and/or `fmt/std.h`
for formatting the container types, like vector, map
optional and variant using {fmt} instead of the homebrew
formatter based on operator<<.
with this change, the changes adding fmt::formatter and
the changes using ostream formatter explicitly, we are
allowed to drop `FMT_DEPRECATED_OSTREAM` macro.
Refs scylladb#13245
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
get0() dates back from the days where Seastar futures carried tuples, and
get0() was a way to get the first (and usually only) element. Now
it's a distraction, and Seastar is likely to deprecate and remove it.
Replace with seastar::future::get(), which does the same thing.
database::get_token_metadata() is switched to token_metadata2.
get_all_ips method is added to the host_id-based token_metadata, since
its convenient and will be used in several places. It returns all current
nodes converted to inet_address by means of the topology
contained within token_metadata.
hint_sender::can_send: if the node has already left the
cluster we may not find its host_id. This case is handled
in the same way as if it's not a normal token owner - we
simply send a hint to all replicas.
Fixes some typos as found by codespell run on the code.
In this commit, I was hoping to fix only comments, not user-visible alerts, output, etc.
Follow-up commits will take care of them.
Refs: https://github.com/scylladb/scylladb/issues/16255
Signed-off-by: Yaniv Kaul <yaniv.kaul@scylladb.com>
This commit makes with_file_update_mutex() a method of hint_endpoint_manager
and introduces db::hints::manager::with_file_update_mutex_for() for accessing
it from the outside. This way, hint_endpoint_manager is hidden and no one
needs to know about its existence.
This commit makes the function less compact and abides by the limit
of 120 characters per line; that makes the code more readable.
We start using fmt::to_string instead of seastar::format("{:d"})
to convert strings to integers -- the new way is the preferred one.
The changes also name variables in a more descriptive way.
This commit makes the function less compact and abides by the limit
of 120 characters per line. That makes the code more readable.
It also doesn't unnecessarily call c_str() on seastar::sstring.
There is no need to call c_str() on the name of the directory entry.
In fact, the used overload std::stoi() takes an std::string as its
argument. Providing seastar::sstring instead of const char* is more
efficient because we can allocate just the right amount of memory
and std::memcpy it, i.e. call std::string(const char*, std::size_t).
Using the overload std::string(const char*) would need to first
traverse the string to find the null byte.
This is a small change, all the more because paths don't tend to
be long, but it's some gain nonetheless.
The commit also inserts a few empty lines to make the code less
compact and improve readability as a result.
An anonymous namespace is a safer mechanism than the static
keyword. When adding a new piece of code, it's easy to
forget about adding the static. In that case, that code
might undergo external linkage. However, when code is put
in an anonymous namespace (when it should not), the linker
will immediately detect it (in most cases), and
the programmer will be able to spot and fix their mistake
right away.
This commit renames `end_point_hints_manager` to `hint_endpoint_manager`
to be consistent with other names used in the module (they all start
with `hint_`).
This commit continues modularizing manager.hh.
After moving the declaration of sender to a dedicated
header file, these changes move its implementation to
a separate source file.
This commit is yet another step in modularizing manager.hh.
We move the declaration of sender to a dedicated file.
Its implementation will follow in a future commit.
The premise of these changes is the fact that we cannot have
a cycle of #includes.
Because the declaration of `sender` is going to be moved to
a separate header file in a future commit, and because that
header file is going to be included in the file where
`end_point_hints_manager` is declared, we will need to rely
on `end_point_hints_manager` being an incomplete type there.
A consequence of that is that we cannot access any of
`end_point_hints_manager`'s methods.
This commit prepares the ground for it by moving
the definition of the function to the source file where
`end_point_hints_manager` will be a complete type.
This commit continues moving end_point_hints_manager to its
dedicated files. After moving the declaration of the class,
these changes move the implementation.
This commit is yet another step in modularizing manager.hh.
We move the declaration of the class to a dedicated header file.
The implementation will follow in a future commit.
This commit moves types used by shard hint manager
and related to storing hints on disk to another file.
It is yet another step in modularizing manager.hh.
This commit extracts the logger used in manager.cc
to prepare the ground for modularization of manager.hh
into separate smaller files. We want to preserve
the logging behavior (at least for the time being),
which means new files should use the same logger.
These changes serve that purpose.
Currently, data structures used in manager.hh
use their own aliases for gms::inet_address.
It is clear they all should use the same type
and having different names for it only reduces
readability of the code. This commit introduces
a common alias -- endpoint_id -- and gets rid
of the other ones.
This commit is also the first step in modularizing
manager.hh by extracting common types to another
file.
