{"action":"created","issue":{"url":"https://api.github.com/repos/couchbaselabs/ForestDB-Benchmark/issues/11","labels_url":"https://api.github.com/repos/couchbaselabs/ForestDB-Benchmark/issues/11/labels{/name}","comments_url":"https://api.github.com/repos/couchbaselabs/ForestDB-Benchmark/issues/11/comments","events_url":"https://api.github.com/repos/couchbaselabs/ForestDB-Benchmark/issues/11/events","html_url":"https://github.com/couchbaselabs/ForestDB-Benchmark/issues/11","id":118639119,"number":11,"title":"transactional guarantees and recoverability","user":{"login":"keithbostic","id":1393186,"avatar_url":"https://avatars.githubusercontent.com/u/1393186?v=3","gravatar_id":"","url":"https://api.github.com/users/keithbostic","html_url":"https://github.com/keithbostic","followers_url":"https://api.github.com/users/keithbostic/followers","following_url":"https://api.github.com/users/keithbostic/following{/other_user}","gists_url":"https://api.github.com/users/keithbostic/gists{/gist_id}","starred_url":"https://api.github.com/users/keithbostic/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/keithbostic/subscriptions","organizations_url":"https://api.github.com/users/keithbostic/orgs","repos_url":"https://api.github.com/users/keithbostic/repos","events_url":"https://api.github.com/users/keithbostic/events{/privacy}","received_events_url":"https://api.github.com/users/keithbostic/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":6,"created_at":"2015-11-24T15:52:48Z","updated_at":"2015-11-29T17:54:38Z","closed_at":null,"body":"What are the transactional guarantees enforced by each of these engines/configurations? I'm asking because:\r\n\r\n* WiredTiger is configured for both checkpointing and the logging, which may or may not make sense,\r\n* WiredTiger's checkpoint frequency is configured to match the LSM engines' compaction frequency, which doesn't make sense,\r\n* WiredTiger is logging to the same disk partition as the data store, which will significantly affect performance."},"comment":{"url":"https://api.github.com/repos/couchbaselabs/ForestDB-Benchmark/issues/comments/160439573","html_url":"https://github.com/couchbaselabs/ForestDB-Benchmark/issues/11#issuecomment-160439573","issue_url":"https://api.github.com/repos/couchbaselabs/ForestDB-Benchmark/issues/11","id":160439573,"user":{"login":"keithbostic","id":1393186,"avatar_url":"https://avatars.githubusercontent.com/u/1393186?v=3","gravatar_id":"","url":"https://api.github.com/users/keithbostic","html_url":"https://github.com/keithbostic","followers_url":"https://api.github.com/users/keithbostic/followers","following_url":"https://api.github.com/users/keithbostic/following{/other_user}","gists_url":"https://api.github.com/users/keithbostic/gists{/gist_id}","starred_url":"https://api.github.com/users/keithbostic/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/keithbostic/subscriptions","organizations_url":"https://api.github.com/users/keithbostic/orgs","repos_url":"https://api.github.com/users/keithbostic/repos","events_url":"https://api.github.com/users/keithbostic/events{/privacy}","received_events_url":"https://api.github.com/users/keithbostic/received_events","type":"User","site_admin":false},"created_at":"2015-11-29T17:54:38Z","updated_at":"2015-11-29T17:54:38Z","body":"> However, it is still not enough to say that it is a fair comparison if the space usage of log files of WiredTiger can largely increase over time (even though they are automatically reclaimed at some time).\r\n\r\nSince the benchmark doesn't concern itself with archival, the WiredTiger log files can be discarded; if WiredTiger approaches disk space limits, perform a single checkpoint and remove all log files other than the most recent.\r\n\r\nAs compression decreases the amount of I/O, WiredTiger log files could be optionally configurable for compression.\r\n\r\n> Of course all DB engines should be configured for their best performance, but the configuration needs to be limited “for given environment”. The major assumption of this benchmark program is that a DB module runs on a single node equipped with a single disk, so DB engines should follow this rule although they are capable to use additional hardware such as different disks or even different machines over network.\r\n\r\nA fair point, but the limitation unavoidably penalizes some engines over others, and where that's the case, I think additional configuration options are strongly justified. (And, I think we agree on that point.) Where we may disagree is I think the high-end server applications these engines target are rarely limited to a single disk, so why make the benchmark's default and only supported configuration a single node?"}}