wbtiger
/
foundationdb
mirror of https://github.com/apple/foundationdb.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

Update documentations and comments

This commit is contained in:
Chaoguang Lin 2022-04-21 10:19:44 -07:00
parent 6bfa4f6ac4
commit 9f110b0f51
2 changed files with 3 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
documentation/sphinx/source/special-keys.rst
View File

@ -191,7 +191,6 @@ that process, and wait for necessary data to be moved away.
#. ``\xff\xff/management/options/excluded/force`` Read/write. Setting this key disables safety checks for writes to ``\xff\xff/management/excluded/<exclusion>``. Setting this key only has an effect in the current transaction and is not persisted on commit.
#. ``\xff\xff/management/options/failed/force`` Read/write. Setting this key disables safety checks for writes to ``\xff\xff/management/failed/<exclusion>``. Setting this key only has an effect in the current transaction and is not persisted on commit.
#. ``\xff\xff/management/min_required_commit_version`` Read/write. Changing this key will change the corresponding system key ``\xff/minRequiredCommitVersion = [[Version]]``. The value of this special key is the literal text of the underlying ``Version``, which is ``int64_t``. If you set the key with a value failed to be parsed as ``int64_t``, ``special_keys_api_failure`` will be thrown. In addition, the given ``Version`` should be larger than the current read version and smaller than the upper bound(``2**63-1-version_per_second*3600*24*365*1000``). Otherwise, ``special_keys_api_failure`` is thrown. For more details, see help text of ``fdbcli`` command ``advanceversion``.
#. ``\xff\xff/management/profiling/<client_txn_sample_rate|client_txn_size_limit>`` (deprecated after 7.2) Read/write. Changing these two keys will change the corresponding system keys ``\xff\x02/fdbClientInfo/<client_txn_sample_rate|client_txn_size_limit>``, respectively. The value of ``\xff\xff/management/client_txn_sample_rate`` is a literal text of ``double``, and the value of ``\xff\xff/management/client_txn_size_limit`` is a literal text of ``int64_t``. A special value ``default`` can be set to or read from these two keys, representing the client profiling is disabled. In addition, ``clear`` in this range is not allowed. For more details, see help text of ``fdbcli`` command ``profile client``.
#. ``\xff\xff/management/maintenance/<zone_id> := <seconds>`` Read/write. Set/clear a key in this range will change the corresponding system key ``\xff\x02/healthyZone``. The value is a literal text of a non-negative ``double`` which represents the remaining time for the zone to be in maintenance. Commiting with an invalid value will throw ``special_keys_api_failure``. Only one zone is allowed to be in maintenance at the same time. Setting a new key in the range will override the old one and the transaction will throw ``special_keys_api_failure`` error if more than one zone is given. For more details, see help text of ``fdbcli`` command ``maintenance``.
In addition, a special key ``\xff\xff/management/maintenance/IgnoreSSFailures`` in the range, if set, will disable datadistribution for storage server failures.
It is doing the same thing as the fdbcli command ``datadistribution disable ssfailure``.
@ -271,16 +270,12 @@ Deprecation
Below are the deprecated special keys and related informations.
#. ``\xff\xff/management/profiling/<client_txn_sample_rate|client_txn_size_limit>`` Deprecated in version 7.2. The corresponding functionalities are now covered by the global configuration module. For details, see :doc:`global-configuration`.
#. ``\xff\xff/management/profiling/<client_txn_sample_rate|client_txn_size_limit>`` Deprecated as of 7.2. The corresponding functionalities are now covered by the global configuration module. For details, see :doc:`global-configuration`. Read/write. Changing these two keys will change the corresponding system keys ``\xff\x02/fdbClientInfo/<client_txn_sample_rate|client_txn_size_limit>``, respectively. The value of ``\xff\xff/management/client_txn_sample_rate`` is a literal text of ``double``, and the value of ``\xff\xff/management/client_txn_size_limit`` is a literal text of ``int64_t``. A special value ``default`` can be set to or read from these two keys, representing the client profiling is disabled. In addition, ``clear`` in this range is not allowed. For more details, see help text of ``fdbcli`` command ``profile client``.
Versioning
=================
For how FDB clients deal with versioning, see :ref:`api-versions`.
The special key space deals with the versioning by using the ``API_VERSION`` that passed to initilialize the client.
The framework will ingore all modules added at the version larger than the api version set by the client.
For example, if a module is added in version 7.0 but the client set the api version as 6.3, then the module it not available to the client.
According to the definition of this contract, anytime you want to remove or update existing modules, you need to keep the old implementation to let the client get the same behavior when it's using the old api version.
For how FDB clients deal with versioning, see :ref:`api-versions`. The special key space deals with the versioning by using the ``API_VERSION`` that passed to initilialize the client. The framework will ingore all modules added at the version larger than the api version set by the client. For example, if a module is added in version 7.0 but the client set the api version as 6.3, then the module it not available to the client. According to the definition of this contract, anytime you want to remove or update existing modules, you need to keep the old implementation to let the client get the same behavior when it's using the old api version.
- To remove a certain module, specify the API version where the function is being deprecated in the ``registerSpecialKeySpaceModule`` function. When a client specifies an API version greater than or equal to the deprecation version, the module will not be available.
- To update the implementation of any modules, add the new implementation and use ``API_VERSION`` to switch between different implementations.

2
fdbclient/SpecialKeySpace.actor.h
View File

@ -485,7 +485,7 @@ public:
Future<Optional<std::string>> commit(ReadYourWritesTransaction* ryw) override;
};
// Deprecated after 7.2
// Deprecated as of 7.2
class ClientProfilingImpl : public SpecialKeyRangeRWImpl {
public:
explicit ClientProfilingImpl(KeyRangeRef kr);