[/map {"- map/map "}) [/map/topicref {"- map/topicref "}) [/map/topicref/topicmeta {"- map/topicmeta "}) [/map/topicref/topicmeta/navtitle {"- topic/navtitle "}) Administering the Dgraph (navtitle][/map/topicref/topicmeta/linktext {"- map/linktext "}) Administering the Dgraph (linktext][/map/topicref/topicmeta/shortdesc {"- map/shortdesc "}) This section describes the Dgraph component in BDD, its administrative operations, and flags. It also describes various Dgraph characteristics and behavior, such as memory consumption, Dgraph cache, 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 is a component of Big Data Discovery that runs search analytical processing of the data sets. It handles query requests users make to data sets. (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 "}) Tips for setting the Dgraph cache size (navtitle][/map/topicref/topicref/topicmeta/linktext {"- map/linktext "}) Tips for setting the Dgraph cache size (linktext][/map/topicref/topicref/topicmeta/shortdesc {"- map/shortdesc "}) Set the Dgraph cache size to be large enough to let the Dgraph 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 "}) Changing the Dgraph memory limit (navtitle][/map/topicref/topicref/topicmeta/linktext {"- map/linktext "}) Changing the Dgraph memory limit (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 you change the memory limit, 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 up cgroups for the Dgraph (navtitle][/map/topicref/topicref/topicmeta/linktext {"- map/linktext "}) Setting up cgroups for the Dgraph (linktext][/map/topicref/topicref/topicmeta/shortdesc {"- map/shortdesc "}) Control groups, or cgroups, is a Linux kernel feature that enables you to allocate resources like CPU time and system memory to specific processes or groups of processes. If you need to host the Dgraph on nodes running Spark, you must use cgroups to ensure sufficient resources are available to it. (shortdesc] (topicmeta] (topicref][/map/topicref/topicref {"- map/topicref "}) [/map/topicref/topicref/topicmeta {"- map/topicmeta "}) [/map/topicref/topicref/topicmeta/navtitle {"- topic/navtitle "}) Moving the Dgraph databases to HDFS (navtitle][/map/topicref/topicref/topicmeta/linktext {"- map/linktext "}) Moving the Dgraph databases to HDFS (linktext][/map/topicref/topicref/topicmeta/shortdesc {"- map/shortdesc "}) If your Dgraph databases are currently stored on an NFS, you can move them to HDFS. (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 (navtitle][/map/topicref/topicref/topicmeta/linktext {"- map/linktext "}) Appointing a new Dgraph leader (linktext][/map/topicref/topicref/topicmeta/shortdesc {"- map/shortdesc "}) You can use the appointNewDgraphLeader.sh script to appoint a new Dgraph leader for a database. (shortdesc] (topicmeta] (topicref][/map/topicref/topicref {"- map/topicref "}) [/map/topicref/topicref/topicmeta {"- map/topicmeta "}) [/map/topicref/topicref/topicmeta/navtitle {"- topic/navtitle "}) About using Linux ulimit settings for merges (navtitle][/map/topicref/topicref/topicmeta/linktext {"- map/linktext "}) About using Linux ulimit settings for merges (linktext][/map/topicref/topicref/topicmeta/shortdesc {"- map/shortdesc "}) For purposes of merging generation files for the internal Dgraph databases (indexes), it is recommended that you set the Linux option ulimit -v and -m parameters to unlimited. You should also set the -n parameter to 65536. (shortdesc] (topicmeta] (topicref][/map/topicref/topicref {"- map/topicref "}) [/map/topicref/topicref/topicmeta {"- map/topicmeta "}) [/map/topicref/topicref/topicmeta/navtitle {"- topic/navtitle "}) Tips for storing Dgraph core dump files (navtitle][/map/topicref/topicref/topicmeta/linktext {"- map/linktext "}) Tips for storing 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. (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 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]