2013-05-02 12:41:44 +00:00
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`wterl` is an Erlang interface to the WiredTiger database, and is written to
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support a Riak storage backend that uses WiredTiger.
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2012-03-28 02:27:50 +00:00
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Remaining work includes:
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2013-05-02 12:41:44 +00:00
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TODO:
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* Find/fix any code marked "TODO:"
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* Why do we see {error, {eperm, _}} result on wterl:cursor_close/1 during
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fold_objects/4?
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* Why do we see {error, {eperm, _}} result on wterl:cursor_close/1?
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* Why do we see {error, {eperm, _}} result on wterl:cursor_next/1 during
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is_empty/1?
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* Why do we see {error, {eperm, _}} result on wterl:cursor_next_value/1
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during status/1?
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* Why do we see {error, {ebusy, _}} result on wterl:drop/2?
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* Determine a better way to estimate the number of sessions we should
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configure WT for at startup in riak_kv_wterl_backend:max_sessions/1.
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2013-05-02 15:29:37 +00:00
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* Make sure Erlang is optimizing for selective receive in async_nif_enqueue/3
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because in the eLevelDB driver there is a comment: "This cannot be a separate
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function. Code must be inline to trigger Erlang compiler's use of optimized
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selective receive."
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2013-05-02 12:41:44 +00:00
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* Provide a way to configure the cursor options, right now they are
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always "raw,overwrite".
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* Add support for Riak/KV 2i indexes using the same design pattern
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as eLevelDB (in a future version consider alternate schema)
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* If an operation using a shared cursor results in a non-normal error
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then it should be closed/discarded from the recycled pool
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* Cache cursors based on hash(table/config) rather than just table.
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* Finish NIF unload/reload functions and test.
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* Test an upgrade, include a format/schema/WT change.
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* When WT_PANIC is returned first try to unload/reload then driver
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and reset all state, if that fails then exit gracefully.
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2012-03-28 02:27:50 +00:00
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* Currently the `riak_kv_wterl_backend` module is stored in this
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repository, but it really belongs in the `riak_kv` repository.
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2013-05-02 12:41:44 +00:00
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* wterl:truncate/5 can segv, and its tests are commented out
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* Add async_nif and wterl NIF stats to the results provided by the
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stats API
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* Longer term ideas/changes to consider:
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* More testing, especially pulse/qc
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* Riak/KV integration
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* Store 2i indexes in separate tables
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* Store buckets, in separate tables and keep a <<bucket/key>> index
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to ensure that folds across a vnode are easy
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* Provide a drop bucket API call
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* Support key expirey
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* An ets API (like the LevelDB's lets project)
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* Use mime-type to inform WT's schema for key value encoding
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* Other use cases within Riak
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* An AAE driver using WT
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* An ability to store the ring file via WT
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2012-03-28 02:27:50 +00:00
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Deploying
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---------
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You can deploy `wterl` into a Riak devrel cluster using the `enable-wterl`
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script. Clone the `riak` repo, change your working directory to it, and
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then execute the `enable-wterl` script. It adds `wterl` as a dependency,
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runs `make all devrel`, and then modifies the configuration settings of the
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resulting dev nodes to use the WiredTiger storage backend.
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