# Log files

TigerGraph Database captures key information on activities occurring across its different components through log functions that output to log files. These log files are not only helpful in troubleshooting but also serve as an auditory resource. This document gives a high-level overview of TigerGraph’s logging structure and lists some common information one might need to monitor their database services and where to obtain them in the logs.

## Overall Logging Structure

Logs in TigerGraph are stored at `<tigergraph_root_dir>/log/`. TigerGraph’s logs are divided into different folders by the different internal components and each folder corresponds to a different component. Log formats also vary across the different components. In folders where logs are checked often, such as `restpp`, `gsql`, and `admin`, there are three symbolic links that help you quickly get to the most recent log file of that category:

• `log.INFO`

• Contains regular output and errors

• `log.ERROR`

• Contains errors only

• `<component_name>.out`

• Contains all output from the component process

• `log.WARNING` or `log.DEBUG`

• `log.WARNING` contains warnings

• In the`gsql` folder, `log.DEBUG` contains very specific information you only need when certain errors happen

Knowing where certain activities are recorded allows one to use tools such as the Linux `grep` command to easily obtain critical information from your database.

## Log locations on a cluster

In a TigerGraph cluster, each node will only keep logs of activities that took place on the node itself. For example, the GSQL logs on the m1 node will only record events for m1 and are not replicated across the cluster.

For GSQL specifically, the cluster will elect a leader to which all GSQL requests will be forwarded. To check which node is the leader, start by checking the GSQL logs of the m1 node. Check the most recent lines of log.INFO and look for lines containing information about leader switch. For example, the logs below recorded a GSQL leader switch from m2 to m1:

``````I@20210709 13:56:52.214  (GsqlHAHandler.java:231) GSQL leader switches from 'm2' to 'm1' ...
E@20210709 13:56:52.215  (GsqlHAHandler.java:246) GSQL HA leader switches to 'm1', abort and clear all sessions now.
I@20210709 13:56:52.219  (SessionManager.java:197) Abort and clear all sessions...
I@20210709 13:56:52.220  (SessionManager.java:204) All sessions aborted.
I@20210709 13:56:52.224  (GsqlHAHandler.java:283) switched to new leader m1``````

## Monitor request history

All requests made to TigerGraph’s REST endpoints are recorded by the RESTPP logs and Nginx logs. Information available in the logs includes:

• Timestamp of the request

• API request parameters

• Request Status

• User information (when RESTPP authentication is turned on)

RESTPP is responsible for many tasks in the TigerGraph internal architecture and records many internal API calls, which can be hard to distinguish from manual requests. When RESTPP authentication is on, the RESTPP log will record the user information and mark a call if it is made by an internal API. Therefore, you can use the command below to filter for manual requests:

``````# In the restpp log directory
$grep -i "requestinfo" log.INFO | grep -v "__INTERNAL_API__" # All requests exluding the ones made by internal API I0315 21:11:59.666318 14535 handler.cpp:351] RequestInfo|,1.RESTPP_1_1.1615842719666.N,NNN,0,0,0|user:tigergraph|api:v2|function:NoSchema|graph_name:social|libudf: I0315 21:41:36.462616 14541 handler.cpp:351] RequestInfo|,196622.RESTPP_1_1.1615844496462.N,NNN,0,0,0|user:tigergraph|api:v2|function:NoSchema|graph_name:social|libudf:`````` `RequestInfo` contains the ID of the request, which you can use to look up more information on the request : Here is an example of using a request ID to look up a request in the restpp log: ``````$ grep "1615842719666" log.INFO

# Returns all information about the specific request
# RawRequest log is captured at the entry point of a query
I0315 21:11:59.666026 14535 handler.cpp:285] RawRequest|,1.RESTPP_1_1.1615842719666.N,NNN,0,0,0|GET|/echo?parameter1=parameter_value|async = 0|payload_data.size() = 0|api = v2
# RequestInfo log is captured after the request has been parsed,
# and contains information such as username and the function or UDF to run
I0315 21:11:59.666318 14535 handler.cpp:351] RequestInfo|,1.RESTPP_1_1.1615842719666.N,NNN,0,0,0|user:tigergraph|api:v2|function:NoSchema|graph_name:social|libudf:
# ReturnResult is captured when the request has been processed
I0315 21:11:59.666509 14535 requestrecord.cpp:325] ReturnResult|0|0ms|RESTPP|1.RESTPP_1_1.1615842719666.N|user:tigergraph|/echo|graph_id=1&graph_name=social&parameter1=parameter_value|39``````

User management activities, such as logins, role and privilege changes are recorded in the GSQL logs in the folder `gsql`.
To view recent activities, use the symlink `log.INFO`. There is a lot of information in the logs - to filter for information that you need, you can use Linux commands such as `grep` and `tail` For example, to view recent changes in roles, you can run the following command in the `gsql` log directory:
``````$grep -i "role" log.INFO # Returns all lines containing the word "role" # username source IP I@20210312 22:41:16.167 tigergraph|127.0.0.1:45854|00000000077 (BaseHandler.java:133) Received|POST|/gsql/roles?action=grant&role=globaldesigner&name=lennessy|0 I@20210312 22:41:16.863 tigergraph|127.0.0.1:45854|00000000077 (BaseHandler.java:167) Successful|POST|/gsql/roles?action=grant&role=globaldesigner&name=lennessy|application/json; charset=UTF-8|696ms`````` To view login activities, search `log.INFO` for `"login"` instead. ``````$ grep -i "login" log.INFO