# ldb
[](https://travis-ci.org/vitorenesduarte/ldb/)
LDB supports different CRDT replication models:
- state-based
- delta-state-based
- pure-op-based
### Configuration
- __LDB_MODE__:
- `state_based`
- `delta_based`
- `pure_op_based`
- __LDB_DRIVEN_MODE__: see [this](http://haslab.uminho.pt/cbm/files/pmldc-2016-join-decomposition.pdf)
for details on `state_driven` and `digest_driven` algorithms
- `none`
- `state_driven`
- `digest_driven`
- __LDB_STATE_SYNC_INTERVAL__: in `state_based` and `delta_based`
modes, state is propagated every `X` milliseconds
- __LDB_REDUNDANT_DGROUPS__: when set to `true`,
removes redundant state that may be present in the received
delta-groups, using [join-decompositions](http://haslab.uminho.pt/cbm/files/pmldc-2016-join-decomposition.pdf)
- __LDB_DGROUP_BACK_PROPAGATION__: when set to `true`,
avoids back-propagation of delta-groups
- __LDB_DBUFFER_SHRINK_INTERVAL__: in `delta_based` mode,
try to shrink the delta buffer every `X` milliseconds
- __LDB_DBUFFER_SHRINK_MODE__:
- `normal`: remove acknowledged entries in the buffer
- `dummy`: remove all entries in the buffer
(note that this mode is only for evaluation purposes)
- __LDB_METRICS__: metrics are recorded if `true`
|||||
|---------------------------------|-------------------------------------------|-------------------------------------------|-----------------|
| __LDB_MODE__ | `state_based` | `delta_based` | `pure_op_based` |
| __LDB_DRIVEN_MODE__ | `none` / `state_driven` / `digest_driven` | `none` / `state_driven` / `digest_driven` | __NA__ |
| __LDB_STATE_SYNC_INTERVAL__ | `0..` | `0..` | __NA__ |
| __LDB_REDUNDANT_DGROUPS__ | __NA__ | `true` / `false` | __NA__ |
| __LDB_DGROUP_BACK_PROPAGATION__ | __NA__ | `true` / `false` | __NA__ |
| __LDB_DBUFFER_SHRINK_INTERVAL__ | __NA__ | `0..` | __NA__ |
| __LDB_DBUFFER_SHRINK_MODE__ | __NA__ | `normal` / `dummy` | __NA__ |
#### Defaults
- __LDB_MODE__: `state_based`
- __LDB_DRIVEN_MODE__: `none`
- __LDB_STATE_SYNC_INTERVAL__: 1000
- __LDB_REDUNDANT_DGROUPS__: `false`
- __LDB_DGROUP_BACK_PROPAGATION__: `false`
- __LDB_DBUFFER_SHRINK_INTERVAL__: 20000
- __LDB_DBUFFER_SHRINK_MODE__: `normal`
- __LDB_METRICS__: `false`
