From ff31ca2d8663fe471b0609dcdadf8af880c6c689 Mon Sep 17 00:00:00 2001 From: martinsumner Date: Sun, 26 Feb 2017 16:29:55 +0000 Subject: [PATCH] Explain sync option --- README.md | 2 +- docs/FUTURE.md | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/README.md b/README.md index 8e03df0..f44129f 100644 --- a/README.md +++ b/README.md @@ -94,7 +94,7 @@ Unit and current tests in leveled should run with rebar3. Leveled has been test {ok, Bookie} = leveled_bookie:book_start(RootPath, LedgerCacheSize, JournalSize, SyncStrategy) ``` -This will start a new Bookie. It will start and look for existing data files, under the RootPath, and start empty if none exist. A LedgerCacheSize of 2000, a JournlaSize of 500000000 (500MB) and a SyncStrategy of recovr should work OK. +This will start a new Bookie. It will start and look for existing data files, under the RootPath, and start empty if none exist. A LedgerCacheSize of 2000, a JournalSize of 500000000 (500MB) and a SyncStrategy of recovr should work OK. The book_start method should respond once startup is complete. The leveled_bookie module includes the full API for external use of the store. diff --git a/docs/FUTURE.md b/docs/FUTURE.md index 1ab9508..cdef147 100644 --- a/docs/FUTURE.md +++ b/docs/FUTURE.md @@ -12,7 +12,7 @@ The store supports all the required Riak backend capabilities. A number of furt - A bucket size query, which requires traversal only of the Ledger and counts the keys and sums the total on-disk size of the objects within the bucket. -- A PUT flag that allows a truer meaning to the existing DW setting, allowing flushing to disk to be prompted by the need to meet the DW flag, rather than always/never +- A new SW count to operate in parallel to DW, where SW is the number of nodes required to have flushed to disk (not just written to buffer); with SW being configurable to 0 (no vnodes will need to sync this write), 1 (the PUT coordinator will sync, but no other vnodes) or all (all vnodes will be required to sync this write before providing a DW ack). This will allow the expensive disk sync operation to be constrained to the writes for which it is most needed. - Support for a specific Riak tombstone tag where reaping of tombstones can be deferred (by many days) i.e. so that a 'sort-of-keep' deletion strategy can be followed that will eventually garbage collect without the need to hold pending full deletion state in memory.