Dgraph out log

The Dgraph redirects its stdout/stderr output to the log file specified by the Dgraph --out flag. By default, the name and location of the file is:

$BDD_HOME/logs/dgraph.out

You can specify a new out log location by changing the DGRAPH_OUT_FILE parameter in the bdd.conf file and then restarting the Dgraph.

The Dgraph stdout/stderr log includes startup messages as well as warning and error messages. You can increase the verbosity of the log via the Dgraph -v flag.

Dgraph out log format

The format of the Dgraph out log fields are:

Timestamp
Component ID
Message Type
Log Subsystem
Job ID
Message Text

The log entry fields and their descriptions are as follows:

Log entry field	Description	Example
Timestamp	The local date and time when the message was generated, using use the following ISO 8601 extended format: YYYY-MM-DDTHH:mm:ss.sss(+\|-)hh:mm The hours range is 0 to 23 and milliseconds and offset timezones are mandatory.	`2016-03-18T13:25:30.600-04:00`
Component ID	The ID of the component that originated the message. "DGRAPH" is hard-coded for the Dgraph.	`DGRAPH`
Message Type	The type of message (log level): `INCIDENT_ERROR` `ERROR` `WARNING` `NOTIFICATION` `TRACE` `UNKNOWN`	`WARNING`
Log Subsystem	The log subsystem that generated the message.	`{dgraph}`
Job ID	The ID of the job being executed.	`[0]`
Message Text	The text of the log message.	`Starting HTTP server on port: 7010`

Dgraph log subsystems

The log subsystems that can generate log entries in the Dgraph out log are the following:

background_merging — messages about Dgraph database maintenance activity.
bulk_ingest — messages generated by Bulk Load ingest operations.
cluster — messages about ZooKeeper-related cluster operations.
database — messages about Dgraph database operations.
datalayer — messages about Dgraph database file usage.
dgraph — messages related to Dgraph general operations.
eql — messages generated from the EQL, the engine for the BDD query language.
eql_feature — messages providing usage information for certain EQL features.
eve — messages generated from the BDD query evaluator.
http — messages about Dgraph HTTP communication operations.
lexer — messages from the OLT (Oracle Language Technology) subsystem.
splitting — messages resulting from BDD query evaluator's splitting tasks.
ssl — messages generated by the SSL subsystem.
task_scheduler — messages related to the Dgraph task scheduler.
text_search_rel_rank — messages related to Relevance Ranking operations during text searches.
text_search_spelling — messages related to spelling correction operations during text searches.
update — messages related to updates.
workload_manager — messages from the Dgraph Workload Manager.
ws_request — messages related to request exchanges between Web services.
xq_web_service — messages generated from the XQuery-based Web services.

All of these subsystems have a default log level of NOTIFICATION.

Dgraph startup information

The first log entry (that begins with "Starting Dgraph") lists the Dgraph version, startup flags and arguments, and path to the Dgraph databases directory. Later entries log additional start-up information, such as the amount of RAM and the number of logical CPUs on the system, the CPU cache topology, the created Web services, HTTP port number, and Bulk Load port number.

Dgraph shutdown information

As part of the Dgraph shutdown process, the shutdown details are logged, including the total amount of time for the shutdown. For example (note that timestamps have been removed for ease of reading):

DGRAPH  NOTIFICATION  {dgraph}    [0]  Shutdown request received at Wed Oct 5 16:17:42
                                       2016.  Shutdown will complete when all outstanding
                                       jobs are complete.
DGRAPH  WARNING       {cluster}   [0]  Lost connection to ZooKeeper: ZooKeeper connection lost
                                       (zk error -4)
DGRAPH  NOTIFICATION  {cluster}   [0]  Finished closing zk connection
DGRAPH  NOTIFICATION  {database}  [0]  Finished unmounting everything.
DGRAPH  NOTIFICATION  {dgraph}    [0]  All dgraph transactions completed at Wed Oct 5
                                       16:17:43 2016, exiting normally (pid=14789)
DGRAPH  NOTIFICATION  {database}  [0]  Finished unmounting everything.
DGRAPH  NOTIFICATION  {dgraph}    [0]  Overall shutdown took 922 ms

Out log ingest example

The following snippets from a Dgraph out log show the entry format for an ingest operation. Note that timestamps have been removed for ease of reading.

DGRAPH  NOTIFICATION  {cluster}      [0]  Promoting to leader on database edp_cli_edp_c23fdc4c
DGRAPH  NOTIFICATION  {database}     [0]  Mounting database edp_cli_edp_c23fdc4c
DGRAPH  NOTIFICATION  {dgraph}       [0]  Initial DL version: 2
DGRAPH  NOTIFICATION  {bulk_ingest}  [0]  MessageParser created
DGRAPH  NOTIFICATION  {bulk_ingest}  [0]  Start ingest for collection: edp_cli_edp_c23fdc4c 
                                          for database edp_cli_edp_c23fdc4c
DGRAPH  NOTIFICATION  {bulk_ingest}  [0]  Starting bulk ingest operation REPLACE_RECORDS 
                                          for database edp_cli_edp_c23fdc4c
DGRAPH  NOTIFICATION  {bulk_ingest}  [0]  Ending bulk ingest for database edp_cli_edp_c23fdc4c
                                          at client's request
DGRAPH  NOTIFICATION  {bulk_ingest}  [0]  Bulk ingest completed: Added 351 records and 
                                          rejected 0 records, for database edp_cli_edp_c23fdc4c
DGRAPH  NOTIFICATION  {bulk_ingest}  [0]  Final statistics: 0.060 MiB, 1.008 records seconds, 
                                          0.060 MiB/s records throughput, 1.182 total seconds, 
                                          0.051 MiB/s total throughput for database 
                                          edp_cli_edp_c23fdc4c

The bulk_ingest entries show the ingest of a data set with 351 records.