[/map {"- map/map "}) [/map/topicref {"- map/topicref "}) [/map/topicref/topicmeta {"- map/topicmeta "}) [/map/topicref/topicmeta/navtitle {"- topic/navtitle "}) The Dgraph (navtitle][/map/topicref/topicmeta/linktext {"- map/linktext "}) The Dgraph (linktext][/map/topicref/topicmeta/shortdesc {"- map/shortdesc "}) This section describes the Dgraph, its administrative operations and flags. It also describes various Dgraph characteristics and behavior, such as memory consumption, Dgraph cache, the index merge policy, and managing the Dgraph core dump files. (shortdesc] (topicmeta][/map/topicref/topicref {"- map/topicref "}) [/map/topicref/topicref/topicmeta {"- map/topicmeta "}) [/map/topicref/topicref/topicmeta/navtitle {"- topic/navtitle "}) About the Dgraph (navtitle][/map/topicref/topicref/topicmeta/linktext {"- map/linktext "}) About the Dgraph (linktext][/map/topicref/topicref/topicmeta/shortdesc {"- map/shortdesc "}) The Dgraph uses proprietary data structures and algorithms that allow it to provide real-time responses to queries. (shortdesc] (topicmeta] (topicref][/map/topicref/topicref {"- map/topicref "}) [/map/topicref/topicref/topicmeta {"- map/topicmeta "}) [/map/topicref/topicref/topicmeta/navtitle {"- topic/navtitle "}) Memory consumption by the Dgraph (navtitle][/map/topicref/topicref/topicmeta/linktext {"- map/linktext "}) Memory consumption by the Dgraph (linktext][/map/topicref/topicref/topicmeta/shortdesc {"- map/shortdesc "}) This topic discusses the logic used by the Dgraph to control its memory consumption. (shortdesc] (topicmeta] (topicref][/map/topicref/topicref {"- map/topicref "}) [/map/topicref/topicref/topicmeta {"- map/topicmeta "}) [/map/topicref/topicref/topicmeta/navtitle {"- topic/navtitle "}) Setting the limit of Dgraph memory consumption (navtitle][/map/topicref/topicref/topicmeta/linktext {"- map/linktext "}) Setting the limit of Dgraph memory consumption (linktext][/map/topicref/topicref/topicmeta/shortdesc {"- map/shortdesc "}) It is possible to specify the custom memory limit the Dgraph is allowed to use for processing. If the memory limit is changed, this overrides the default memory consumption setting in the Dgraph that is set to 80% of the machine's available RAM. (shortdesc] (topicmeta] (topicref][/map/topicref/topicref {"- map/topicref "}) [/map/topicref/topicref/topicmeta {"- map/topicmeta "}) [/map/topicref/topicref/topicmeta/navtitle {"- topic/navtitle "}) Setting the Dgraph internal cache size (navtitle][/map/topicref/topicref/topicmeta/linktext {"- map/linktext "}) Setting the Dgraph internal cache size (linktext][/map/topicref/topicref/topicmeta/shortdesc {"- map/shortdesc "}) The Dgraph cache size should be configured to be large enough to allow the Dgraph to operate smoothly under normal query load. (shortdesc] (topicmeta] (topicref][/map/topicref/topicref {"- map/topicref "}) [/map/topicref/topicref/topicmeta {"- map/topicmeta "}) [/map/topicref/topicref/topicmeta/navtitle {"- topic/navtitle "}) Managing an index merge policy (navtitle][/map/topicref/topicref/topicmeta/linktext {"- map/linktext "}) Managing an index merge policy (linktext][/map/topicref/topicref/topicmeta/shortdesc {"- map/shortdesc "}) An index merge policy controls how the Dgraph manages its index files. A balanced index merge policy is used by default, and, in the majority of deployments, you do not need to change it. (shortdesc] (topicmeta][/map/topicref/topicref/topicref {"- map/topicref "}) [/map/topicref/topicref/topicref/topicmeta {"- map/topicmeta "}) [/map/topicref/topicref/topicref/topicmeta/navtitle {"- topic/navtitle "}) About an index merge policy (navtitle][/map/topicref/topicref/topicref/topicmeta/linktext {"- map/linktext "}) About an index merge policy (linktext][/map/topicref/topicref/topicref/topicmeta/shortdesc {"- map/shortdesc "}) An index merge policy determines how frequently the Dgraph merges incremental update generations in its index files. (shortdesc] (topicmeta] (topicref][/map/topicref/topicref/topicref {"- map/topicref "}) [/map/topicref/topicref/topicref/topicmeta {"- map/topicmeta "}) [/map/topicref/topicref/topicref/topicmeta/navtitle {"- topic/navtitle "}) Manually forcing a merge (navtitle][/map/topicref/topicref/topicref/topicmeta/linktext {"- map/linktext "}) Manually forcing a merge (linktext][/map/topicref/topicref/topicref/topicmeta/shortdesc {"- map/shortdesc "}) Manually forcing a merge is considered a one-time option, because after the merge operation is performed (via a temporary `aggressive` change to the merge policy), the merge policy reverts to its previous setting. (shortdesc] (topicmeta] (topicref][/map/topicref/topicref/topicref {"- map/topicref "}) [/map/topicref/topicref/topicref/topicmeta {"- map/topicmeta "}) [/map/topicref/topicref/topicref/topicmeta/navtitle {"- topic/navtitle "}) Linux ulimit settings for merges (navtitle][/map/topicref/topicref/topicref/topicmeta/linktext {"- map/linktext "}) Linux ulimit settings for merges (linktext][/map/topicref/topicref/topicref/topicmeta/shortdesc {"- map/shortdesc "}) For purposes of generation merging, it is recommended that you set the Linux option `ulimit` `-v` and `-m` parameters to `unlimited`. (shortdesc] (topicmeta] (topicref] (topicref][/map/topicref/topicref {"- map/topicref "}) [/map/topicref/topicref/topicmeta {"- map/topicmeta "}) [/map/topicref/topicref/topicmeta/navtitle {"- topic/navtitle "}) Managing Dgraph core dump files (navtitle][/map/topicref/topicref/topicmeta/linktext {"- map/linktext "}) Managing Dgraph core dump files (linktext][/map/topicref/topicref/topicmeta/shortdesc {"- map/shortdesc "}) In the rare case of a Dgraph crash, the Dgraph writes its core dump files on disk. It is recommended to use the `ulimit -c unlimited` setting for the Dgraph core dump files. Non-limited core files contain all Dgraph data that is resident in memory (RSS of the Dgraph process). (shortdesc] (topicmeta] (topicref][/map/topicref/topicref {"- map/topicref "}) [/map/topicref/topicref/topicmeta {"- map/topicmeta "}) [/map/topicref/topicref/topicmeta/navtitle {"- topic/navtitle "}) Appointing a new Dgraph leader node (navtitle][/map/topicref/topicref/topicmeta/linktext {"- map/linktext "}) Appointing a new Dgraph leader node (linktext][/map/topicref/topicref/topicmeta/shortdesc {"- map/shortdesc "}) You can use the `appointNewDgraphLeader.sh` script to appoint a new Dgraph leader. (shortdesc] (topicmeta] (topicref][/map/topicref/topicref {"- map/topicref "}) [/map/topicref/topicref/topicmeta {"- map/topicmeta "}) [/map/topicref/topicref/topicmeta/navtitle {"- topic/navtitle "}) About Dgraph statistics (navtitle][/map/topicref/topicref/topicmeta/linktext {"- map/linktext "}) About Dgraph statistics (linktext][/map/topicref/topicref/topicmeta/shortdesc {"- map/shortdesc "}) The Dgraph statistics page provides information such as startup time, host, port, and process information, data and log paths, and so on. This information is useful to help to tune your Dgraph and useful for Oracle Support. (shortdesc] (topicmeta] (topicref][/map/topicref/topicref {"- map/topicref "}) [/map/topicref/topicref/topicmeta {"- map/topicmeta "}) [/map/topicref/topicref/topicmeta/navtitle {"- topic/navtitle "}) Dgraph administrative operations (navtitle][/map/topicref/topicref/topicmeta/linktext {"- map/linktext "}) Dgraph administrative operations (linktext][/map/topicref/topicref/topicmeta/shortdesc {"- map/shortdesc "}) This section describes how to perform administrative operations for the Dgraph using the `bdd-admin` script with the `dgraph-admin` command. (shortdesc] (topicmeta][/map/topicref/topicref/topicref {"- map/topicref "}) [/map/topicref/topicref/topicref/topicmeta {"- map/topicmeta "}) [/map/topicref/topicref/topicref/topicmeta/navtitle {"- topic/navtitle "}) About the dgraph-admin command (navtitle][/map/topicref/topicref/topicref/topicmeta/linktext {"- map/linktext "}) About the dgraph-admin command (linktext][/map/topicref/topicref/topicref/topicmeta/shortdesc {"- map/shortdesc "}) You can perform a number of Dgraph administrative operations by running the `bdd-admin` script with the `dgraph-admin` command. (shortdesc] (topicmeta] (topicref][/map/topicref/topicref/topicref {"- map/topicref "}) [/map/topicref/topicref/topicref/topicmeta {"- map/topicmeta "}) [/map/topicref/topicref/topicref/topicmeta/navtitle {"- topic/navtitle "}) flush (navtitle][/map/topicref/topicref/topicref/topicmeta/linktext {"- map/linktext "}) flush (linktext][/map/topicref/topicref/topicref/topicmeta/shortdesc {"- map/shortdesc "}) `./bdd-admin.sh dgraph-admin flush <hostname>` flushes the Dgraph cache. (shortdesc] (topicmeta] (topicref][/map/topicref/topicref/topicref {"- map/topicref "}) [/map/topicref/topicref/topicref/topicmeta {"- map/topicmeta "}) [/map/topicref/topicref/topicref/topicmeta/navtitle {"- topic/navtitle "}) merge (navtitle][/map/topicref/topicref/topicref/topicmeta/linktext {"- map/linktext "}) merge (linktext][/map/topicref/topicref/topicref/topicmeta/shortdesc {"- map/shortdesc "}) `./bdd-admin.sh dgraph-admin merge [merge policy] <hostname>` merges update generations in the index. (shortdesc] (topicmeta] (topicref][/map/topicref/topicref/topicref {"- map/topicref "}) [/map/topicref/topicref/topicref/topicmeta {"- map/topicmeta "}) [/map/topicref/topicref/topicref/topicmeta/navtitle {"- topic/navtitle "}) stickymerge (navtitle][/map/topicref/topicref/topicref/topicmeta/linktext {"- map/linktext "}) stickymerge (linktext][/map/topicref/topicref/topicref/topicmeta/shortdesc {"- map/shortdesc "}) `./bdd-admin.sh dgraph-admin stickymerge <merge policy> <hostname>` changes the merge policy to the specified policy and forces a merge. (shortdesc] (topicmeta] (topicref][/map/topicref/topicref/topicref {"- map/topicref "}) [/map/topicref/topicref/topicref/topicmeta {"- map/topicmeta "}) [/map/topicref/topicref/topicref/topicmeta/navtitle {"- topic/navtitle "}) stats (navtitle][/map/topicref/topicref/topicref/topicmeta/linktext {"- map/linktext "}) stats (linktext][/map/topicref/topicref/topicref/topicmeta/shortdesc {"- map/shortdesc "}) `./bdd-admin.sh dgraph-admin stats <hostname>` returns the Dgraph statistics page. (shortdesc] (topicmeta] (topicref][/map/topicref/topicref/topicref {"- map/topicref "}) [/map/topicref/topicref/topicref/topicmeta {"- map/topicmeta "}) [/map/topicref/topicref/topicref/topicmeta/navtitle {"- topic/navtitle "}) statsreset (navtitle][/map/topicref/topicref/topicref/topicmeta/linktext {"- map/linktext "}) statsreset (linktext][/map/topicref/topicref/topicref/topicmeta/shortdesc {"- map/shortdesc "}) `./bdd-admin.sh dgraph-admin statsreset <hostname>` resets the Dgraph statistics. (shortdesc] (topicmeta] (topicref][/map/topicref/topicref/topicref {"- map/topicref "}) [/map/topicref/topicref/topicref/topicmeta {"- map/topicmeta "}) [/map/topicref/topicref/topicref/topicmeta/navtitle {"- topic/navtitle "}) logroll (navtitle][/map/topicref/topicref/topicref/topicmeta/linktext {"- map/linktext "}) logroll (linktext][/map/topicref/topicref/topicref/topicmeta/shortdesc {"- map/shortdesc "}) `./bdd-admin.sh dgraph-admin logroll <hostname>` forces a query logroll. This reinitializes the query log and archives the old log file. (shortdesc] (topicmeta] (topicref][/map/topicref/topicref/topicref {"- map/topicref "}) [/map/topicref/topicref/topicref/topicmeta {"- map/topicmeta "}) [/map/topicref/topicref/topicref/topicmeta/navtitle {"- topic/navtitle "}) log-status (navtitle][/map/topicref/topicref/topicref/topicmeta/linktext {"- map/linktext "}) log-status (linktext][/map/topicref/topicref/topicref/topicmeta/shortdesc {"- map/shortdesc "}) `./bdd-admin.sh dgraph-admin log-status <hostname>` returns a list of all possible logging variables with their statuses indicated by `true` or `false`. (shortdesc] (topicmeta] (topicref][/map/topicref/topicref/topicref {"- map/topicref "}) [/map/topicref/topicref/topicref/topicmeta {"- map/topicmeta "}) [/map/topicref/topicref/topicref/topicmeta/navtitle {"- topic/navtitle "}) log-enable (navtitle][/map/topicref/topicref/topicref/topicmeta/linktext {"- map/linktext "}) log-enable (linktext][/map/topicref/topicref/topicref/topicmeta/shortdesc {"- map/shortdesc "}) `./bdd-admin.sh dgraph-admin log-enable <features> <hostname>` enables the specified extended logging features. (shortdesc] (topicmeta] (topicref][/map/topicref/topicref/topicref {"- map/topicref "}) [/map/topicref/topicref/topicref/topicmeta {"- map/topicmeta "}) [/map/topicref/topicref/topicref/topicmeta/navtitle {"- topic/navtitle "}) log-disable (navtitle][/map/topicref/topicref/topicref/topicmeta/linktext {"- map/linktext "}) log-disable (linktext][/map/topicref/topicref/topicref/topicmeta/shortdesc {"- map/shortdesc "}) `./bdd-admin.sh dgraph-admin log-disable <features> <hostname>` disables the specified extended logging features. (shortdesc] (topicmeta] (topicref] (topicref][/map/topicref/topicref {"- map/topicref "}) [/map/topicref/topicref/topicmeta {"- map/topicmeta "}) [/map/topicref/topicref/topicmeta/navtitle {"- topic/navtitle "}) Dgraph flags (navtitle][/map/topicref/topicref/topicmeta/linktext {"- map/linktext "}) Dgraph flags (linktext][/map/topicref/topicref/topicmeta/shortdesc {"- map/shortdesc "}) Dgraph flags modify the Dgraph's configuration and behavior. (shortdesc] (topicmeta] (topicref][/map/topicref/topicref {"- map/topicref "}) [/map/topicref/topicref/topicmeta {"- map/topicmeta "}) [/map/topicref/topicref/topicmeta/navtitle {"- topic/navtitle "}) Dgraph HDFS Agent flags (navtitle][/map/topicref/topicref/topicmeta/linktext {"- map/linktext "}) Dgraph HDFS Agent flags (linktext][/map/topicref/topicref/topicmeta/shortdesc {"- map/shortdesc "}) This topic describes the flags used by the Dgraph HDFS Agent. (shortdesc] (topicmeta] (topicref] (topicref] (map]