The information required for the provider to process periodic polling requests is contained in the synchronization cookie of the request itself. In its basic refreshOnly synchronization mode, the provider uses pull-based synchronization where the consumer servers need not be tracked and no history information is maintained. Syncrepl supports both pull-based and push-based synchronization. Syncrepl can automatically resynchronize the consumer database to be up-to-date with the current provider content. The consumer database can be constructed from a consumer-side or a provider-side backup at any synchronization status. Syncrepl also enables convenient management of consumers by maintaining replication status. Because the syncrepl consumer and provider maintain their content status, the consumer can poll the provider content to perform incremental synchronization by asking for the entries required to make the consumer up-to-date with the provider content. Syncrepl keeps track of the status of the replication content by maintaining and exchanging synchronization cookies. Since the protocol does not require a history store, the provider does not need to maintain any log of updates it has received (Note that the syncrepl engine is extensible and additional replication protocols may be supported in the future.). In push-based replication the consumer listens for updates that are sent by the provider in realtime. In pull-based replication the consumer periodically polls the provider for updates. LDAP Sync provides a stateful replication which supports both pull-based and push-based synchronization and does not mandate the use of a history store. Syncrepl uses the LDAP Content Synchronization protocol (or LDAP Sync for short) as the consumer synchronization protocol. It creates and maintains a replica by connecting to the replication provider to perform the initial DIT content load followed either by periodic content polling or by timely updates upon content changes. A syncrepl engine resides at the consumer and executes as one of the slapd(8) threads. The LDAP Sync Replication engine, syncrepl for short, is a consumer-side replication engine that enables the consumer LDAP server to maintain a shadow copy of a DIT fragment. The following sections will describe the replication technology and discuss the various replication options that are available.ġ8.1. Also, a consumer need not be an actual LDAP server it may be just an LDAP client. Unlike the rigidly defined master/slave relationships, provider/consumer roles are quite fluid: replication updates received in a consumer can be further propagated by that consumer to other servers, so a consumer can also act simultaneously as a provider. Another historic term introduced with OpenLDAP 2.4 was multimaster.Īs OpenLDAP now supports a wide variety of replication topologies, these terms have been deprecated in favor of provider/ multi-provider and consumer: A provider can accept external write operations and make them available for retrieval by consumers consumers request replication updates from providers. The replication structure was rigidly defined and any particular database could only fulfill a single role, either master or slave. A master accepted directory updates from other clients, and a slave only accepted updates from a (single) master. In previous releases, replication was discussed in terms of a master server and some number of slave servers. OpenLDAP has various configuration options for creating a replicated directory. Replicated directories are a fundamental requirement for delivering a resilient enterprise deployment.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |