Inspect YugabyteDB logs
YugabyteDB has an extensive error-handling mechanism, with logging being one of its main components.
YugabyteDB base folder
The logs for each node are written to a subdirectory of the YugabyteDB yugabyte-data
directory and may vary depending on your deployment, as follows:
- When you use
yb-ctl
to create local YugabyteDB clusters on a single host (for example, your computer), the default location for each node is/yugabyte-data/node-<node_nr>/
. For a 3-node cluster, theyb-ctl
utility creates three directories:node-1
,node-2
,node-3
. - For a multi-node cluster deployment to multiple hosts, the location where YugabyteDB disks are set up can vary (for example,
/home/centos/
,/mnt/
, or another directory) on each node (host). - When using the
--fs_data_dirs
flag with multiple directories, logs are saved in the first directory in the list. - When using YugabyteDB Anywhere, logs are located in
/home/yugabyte/{master,tserver}/logs
. This is a symlink to the first directory in--fs_data_dirs
list. - When using the Docker container, logs are located in
/root/var/logs
inside the container. - When using the
yugabyted
command-line interface to create the local YugabyteDB cluster, logs are located in~/var/logs
.
In this document, the YugabyteDB yugabyte-data
directory is represented by <yugabyte-data-directory>
.
YB-Master logs
The YB-Master service manages system metadata, such as namespaces (databases or keyspaces) and tables. It also handles Data Definition Language (DDL) statements such as CREATE TABLE
, DROP TABLE
, ALTER TABLE
, KEYSPACE/TYPE
. In addition, it manages users, permissions, and coordinate background operations, such as load balancing. You can access these logs as follows:
cd <yugabyte-data-directory>/disk1/yb-data/master/logs/
Logs are organized by error severity: FATAL
, ERROR
, WARNING
, INFO
.
YB-TServer logs
The YB-TServer service performs the actual input-output for end-user requests. It handles Data Manipulation Language (DML) statements such as INSERT
, UPDATE
, DELETE
, and SELECT
. You can access these logs as follows:
cd <yugabyte-data-directory>/disk1/yb-data/tserver/logs/
Logs are organized by error severity: FATAL
, ERROR
, WARNING
, INFO
.
Logs management
For YB-Master and YB-TServer, the log rotation size is controlled by the --max_log_size
flag. For example, setting this flag to 256 limits each file to 256 MB. The default size is 1.8 GB.
For YSQL, there are additional postgres*log
files that have daily-based and size-based log rotation. That is, a new log file is created every day or when a log reaches 10 MB in size.
For information on available configuration flags, see YB-Master logging flags and YB-TServer logging flags.
Log format
YB-Master and YB-TServer log messages follow this pattern:
Lmmdd hh:mm:ss.uuuuuu threadid file:line] msg
The fields are as follows:
L
: A single character, representing the log level (I
for INFO,W
for WARNING,E
for ERROR, andF
for FATAL).mm
: Month (zero-padded; for example, May is05
).dd
: Day (zero-padded).hh:mm:ss.uuuuuu
: Time in hours, minutes, and fractional seconds.threadid
: Thread ID.file
: File name.line
: Line number.msg
: The logged message.