Adds support to TaggedCache to support smart replacement
(Needed to avoid race conditions with negative caching.)
Create a "hotDUMMY" object that represents the absence
of an object.
Allow DatabaseNodeImp::asyncFetch to complete immediately
if object is in cache (positive or negative).
Fix a bug in asyncFetch where the object returned may not
be the correct canonical version because we stash the
object in the results array before we canonicalize it.
The nodestore includes a built-in cache to reduce the disk I/O
load but, by default, this cache was not initialized unless it
was explicitly configured by the server operator.
This commit introduces sensible defaults based on the server's
configured node size.
It remains possible to completely disable the cache if desired
by explicitly configuring it the cache size and age parameters
to 0:
[node_db]
...
cache_size = 0
cache_age = 0
- Only duplicate records from archive to writable during online_delete.
- Log duration of nodestore reads.
- Include nodestore counters in perf_log output.
- Remove gratuitous nodestore activity counting.
- Report initial sync duration in server_info and perfLog.
- Report state_accounting in perfLog.
- Make state_accounting durations more accurate.
- Parallel ledger loader.
- Config parameter to load ledgers on start.
* Add a new operating mode to rippled called reporting mode
* Add ETL mechanism for a reporting node to extract data from a p2p node
* Add new gRPC methods to faciliate ETL
* Use Postgres in place of SQLite in reporting mode
* Add Cassandra as a nodestore option
* Update logic of RPC handlers when running in reporting mode
* Add ability to forward RPCs to a p2p node
This comment explains this patch and the associated patches
that should be folded into it. This paragraph should be removed
when the patches are folded after review.
This change significantly improves ledger sync and fetch
times while reducing memory consumption. The change affects
the code from that begins with SHAMap::getMissingNodes and runs
through to Database::threadEntry.
The existing code issues a number of async fetches which are then
handed off to the Database's pool of read threads to execute.
The results of each read are placed in the Database's positive
and negative caches. The caller waits for all reads to complete
and then retrieves the results out of these caches.
Among other issues, this means that the results of the first read
cannot be processed until the last read completes. Additionally,
all the results must sit in memory.
This patch changes the behavior so that each read operation has a
completion handler associated with it. The completion of the read
calls the handler, allowing the results of each read to be
processed as it completes. As this was the only reason the
negative and positive caches were needed, they can now be removed.
The read generation code is also no longer needed and is removed.
The batch fetch logic was never implemented or supported and is
removed.
* canonicalize_replace_cache
* canonicalize_replace_client
Now it is clear at the call site that if there are
duplicate copies of the data between the cache and
the caller, which copy gets replaced.
Additionally data parameter is now const-correct.
If it is not going to be replaced (canonicalize_replace_cache),
then the shared_ptr to the client data is const.
* Reduce lock scope on all public functions
* Use TaskQueue to process shard finalization in separate thread
* Store shard last ledger hash and other info in backend
* Use temp SQLite DB versus control file when acquiring
* Remove boost serialization from cmake files
