The reference is put on the snitch_ptr because this is the sharded<>
thing and because gossiper reference is the same for different snitch
drivers. Also, getting gossiper from snitch_ptr by driver will look
simpler than getting it from any base class.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
After previous patches both, create_snitch() and stop_snitch() no look
like the classica sharded service start/stop sequence. Finally both
helpers can be removed and the rest of the user can just call start/stop
on locally obtained sharded references.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
Both first stop/pause snitch driver on io-ing shard, then proceed with
the rest. This sequence is pretty pointless and here's why.
The only non-trivial stop()/pause_io() method out there is in the
property-file snitch driver. In it, both methods check if the current
shard is the io-ing one, if no -- return back the resolved future, if
yes -- go ahead and stop/pause some IO. With this, for all shards but
io-ing one there's no point in starting after io-ing one is stopped,
they all can start (and finish) in parallel.
So what this patch does is just removes the pre-stop/pause kicking of
the io-ing shard.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
Current API to create snitch is not like other services -- there's a
dedicated helper that does sharded<>.start() + invoke_on_all(&start)
calls. These helpers complicate do-globalization of snitch and rework
of services start-stop sequence, things get simpler if snitch uses
the same start-stop API as all the others. The first step towards this
change is moving the non-waiting parts of snitch initialization code
from init_snitch_obj() into snitch_ptr constructor.
A note on this change: after patch #2 the snitch_ptr<->driver linkage
connects local objects with each other, not container() of any. This
is important, because connecting container() would be impossible inside
constructor, as the container pointer is initialized by seastar _after_
the service constructor itself.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
This virtual method returns back the list of app states that snitch
drivers need to gossip around. The exact implementation copies the
gossip_snitch_info() logic of the respective drivers and is unused.
Next patches will make use of it (spoiler: the latter method will be
removed after that).
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
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
storage_proxy works with vectors of inet_addresses for replica sets
and for topology changes (pending endpoints, dead nodes). This patch
introduces new names for these (without changing the underlying
type - it's still std::vector<gms::inet_address>). This is so that
the following patch, that changes those types to utils::small_vector,
will be less noisy and highlight the real changes that take place.
This is the 2nd step in generalizing the snitch data gossiping
and at the same the 1st step in decoupling storage service and
snitch.
During start storage service starts gossiper, which notifies the
snicth with .gossiper_starting() call, then the storage service
calls gossip_snitch_info.
This patch makes snitch itself do the last step.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
Nowadays some snitch implementations gossip the INTERNAL_IP
value and storage_service gossip RACK and DC for all of them.
This functionality is going to be generalized and the first
step is in making a common method for a snitch to gossip its
data.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
Snitch forms a class hierarchy which get_shard_count and
get_ignore_msb_bits ignore (their returned values only depend on the
gossiper's state).
Besides, these functions just don't belong there.
Snitch has nothing to do with shard_count or ignore_msb_bits.
We need the mapping between dht::token_range to
std::vector<inet_address> and inet_address to dht::token_range_vector in
various places. Currently, we use std::unordered_multimap and convert to
std::unordered_map. It is better to use std::unordered_map in the first
place. The changes like below:
- Change from
std::unordered_multimap<dht::token_range, inet_address>
to
std::unordered_map<dht::token_range, std::vector<inet_address>>
- Change from
std::unordered_multimap<inet_address, dht::token_range>
to
std::unordered_map<inet_address, dht::token_range_vector>
Message-Id: <b8ecc41775e46ec064db3ee07510c404583390aa.1533106019.git.asias@scylladb.com>
The logger class constructor registers itself with the logger registry,
in order to enable dynamically setting log levels. However, since
thread_local variables may be (and are) initialized at the time of first
use, when the program starts up no loggers are registered.
Fix by making loggers global, not thread_local. This requires that the
registry use locking to prevent registration happening on different threads
from corrupting the registry.
Note that technically global variables can also be initialized at the
point of first use, and there is no portable way for classes to self-register.
However this is the best we can do.
Snitch class semantics defined to be per-Node. To make it so we
introduce here a static member in an i_endpoint_snitch class that
has to contain the pointer to the relevant snitch class instance.
Since the snitch contents are not always pure const it has to be per
shard, therefore we'll make it a "distributed". All the I/O is going
to take place on a single shard and if there are changes - they are going
to be propagated to the rest of the shards.
The application is responsible to initialize this distributed<shnitch>
before it's used for the first time.
This patch effectively reverts most of the "locator: futurize
snitch creation" a2594015f9 patch - the part that modifies the
code that was creating the snitch instance. Since snitch is
created explicitly by the application and all the rest of the code
simply assumes that the above global is initialized we won't need
all those changes any more and the code will get back to be nice and simple
as it was before the patch above.
So, to summarize, this patch does the following:
- Reverts the changes introduced by a2594015f9 related to the fact that
every time a replication strategy was created there should have been created
a snitch that would have been stored in this strategy object. More specifically,
methods like keyspace::create_replication_strategy() do not return a future<>
any more and this allows to simplify the code that calls it significantly.
- Introduce the global distributed<snitch_ptr> object:
- It belongs to the i_endpoint_snitch class.
- There has been added a corresponding interface to access both global and
shard-local instances.
- locator::abstract_replication_strategy::create_replication_strategy() does
not accept snitch_ptr&& - it'll get and pass the corresponding shard-local
instance of the snitch to the replication strategy's constructor by itself.
- Adjusted the existing snitch infrastructure to the new semantics:
- Modified the create_snitch() to create and start all per-shard snitch
instances and update the global variable.
- Introduced a static i_endpoint_snitch::stop_snitch() function that properly
stops the global distributed snitch.
- Added the code to the gossiping_property_file_snitch that distributes the
changed data to all per-shard snitch objects.
- Made all existing snitches classes properly maintain their state in order
to be able to shut down cleanly.
- Patched both urchin and cql_query_test to initialize a snitch instance before
all other services.
Signed-off-by: Vlad Zolotarov <vladz@cloudius-systems.com>
New in v6:
- Rebased to the current master.
- Extended a commit message a little - the summary.
New in v5:
- database::create_keyspace(): added a missing _keyspaces.emplace()
New in v4:
- Kept the database::create_keyspace() to return future<> by Glauber's request
and added a description to this method that needs to be changed when Glauber
adds his bits that require this interface.
- Introduce snitch_base class that implements all snitch functionality
except for get_rack() and get_datacenter() methods.
- Requires the inheriting classes to initialize _my_rack and _my_dc fields.
Signed-off-by: Vlad Zolotarov <vladz@cloudius-systems.com>
New in v2:
- Returned copyright lines.
- Make _my_dc and _my_rack a non-optional for now.
- Styling and add an "override" qualifier to virtual functions implementations.
- Move most of snitch_base members into snitch_base.cc.
- snitch_base.hh: Add "Modified by Cloudius Systems" to a license.
- simple_snitch: copyright
- rack_inferring_snitch: copyright
