If you have any trouble with VividCortex and the answers below don’t resolve it, please contact us with the chat icon in the bottom left navigation bar.
I see data in the Profiler, but I don’t see charts.
You can see the queries because there are two database-specific plugins. One plugin
decodes the database network protocol, recording queries directly, so it
doesn’t need credentials. On the other hand, the metrics plugin needs to connect to the
database to get the server’s status and other data, so it needs credentials. If
you don’t see any charts with database status metrics, it’s likely that the agent is having trouble
logging into the database to get the status metrics. Check the Events dashboard for any
information the agent may have sent about its error, or check
/var/log/vividcortex/ for any error messages.
I provided credentials, but the agent cannot connect.
First, please double-check that you have created a user correctly in your database and can
log in as that user with the specified password. To verify this in MySQL, which
has “anonymous” users that can cause unexpected results, issue the
GRANTS command after logging in. The column name should be something like
Grants for user@host. Verify that this is as expected.
A common problem with this process in MySQL is specifying which host the agent is allowed
to connect from. The VividCortex agent will only connect over TCP/IP, not a Unix
socket. If you’ve specified the allowed host in the
GRANT statement as
user@locahost, then you’ve created a MySQL user account that only permits Unix
socket logins. You will need to specify a hostname or IP address, such as
firstname.lastname@example.org, to permit a TCP/IP login.
You can check to mimic how the agent will log into the database server, substituting appropriate values below:
$ mysql --protocol=tcp -uUSER -pPASSWORD -hHOST --port=PORT ERROR 1045 (28000): Access denied for user 'USER'@'127.0.0.1' (using password: YES)
Please note the user from which access was denied. If this doesn’t match how you’ve created the user, that could be the problem.
You may also have specified a wrong host, such as specifying
127.0.0.1 for the
host to which the agent should connect, when MySQL is not listening on that IP
address. If this is the case, you’ll get an error message similar to this:
ERROR 2003 (HY000): Can't connect to MySQL server on 'HOST' (61)
After you get everything working, please be sure to remove any unwanted users, and be sure to grant all necessary privileges to the new user you create to replace it.
I do not see queries that I know are executing.
Our agent only captures queries sent to the server over unencrypted TCP/IP connections, not Unix sockets. We won’t see the following types of queries:
- Queries sent to
localhostover a Unix socket
- Queries sent over an encrypted connection
- Queries executed from stored routines (stored procedures, events, or triggers)
- Queries that execute via replication
We don’t analyze server log files to capture queries; read more about why if you are curious.
If none of the above seems to be the culprit, something else may be happening. Contact us and we will troubleshoot right away.
I was invited to join VividCortex, but my invitation expired.
When someone invites you to join a VividCortex account, the invitation sent to your email is valid for 10 days. We can help you renew it if necessary.
I do not see agents installed on a new host.
If you’re using a free trial or you’re on a capped contract, you may have
exceeded your quota. Check the
/var/log/vividcortex/vc-agent-007.log log file
for messages to that effect. Contact us if you need to increase your quota or if
you’re interested in evaluating VividCortex on more hosts during your trial.
Also see Missing Hosts on the Managing Hosts page.
How do I remove hosts?
If you’d like to deactivate a host so it doesn’t contribute towards your usage quota, you can do so with the following steps:
- Select the host in the Hosts Dashboard, and click on the gear that appears to the right of its name. You will see a popup like the one below:
- Check the box labeled “I know what I’m doing”, and click on the Delete button to confirm deletion. Once deleted a host will automatically be removed from your license count.
You may also uninstall the agents and wait a bit; because usage is metered by the hour, the number of active hosts in use will decrease after two hours.
I don’t see my MongoDB sharded cluster.
We use the
shardingState command in MongoDB to determine if a node is a member of a
sharded cluster. In order for this command to provide us the information we need, MongoDB
instances must be configured to run as shards using the
--shardsvr option or the
sharding.clusterRole configuration file setting, as specified by the MongoDB docs.
To read more about this requirement, please visit the official MongoDB documentation,
which can be found here.
Why don’t I see any database or table size metrics in the Profiler?
Database and table size metrics, such as
index_length, are disabled by default as collecting those
metrics can be costly. To enable them, you can either contact VividCortex Customer Support (recommended) by chatting with
us using the ? button in the lower right corner, or you can enable table sizes using a VividCortex config file
with the option
enable-table-sizes. This option applies to the
Why don’t I see any InnoDB mutex data?
If you do not see any data reported in the Profiler or Metrics pages for InnoDB mutexes, check that the
wait/synch/mutex/innodb/% instruments are enabled in
performance_schema. To check if these are enabled, execute:
SELECT * FROM performance_schema.setup_instruments where NAME like 'wait/synch/mutex/innodb/%'
To enable these instruments, you can either add
my.cnf or execute:
UPDATE performance_schema.setup_instruments SET ENABLED='YES' WHERE NAME LIKE 'wait/synch/mutex/innodb/%';
The instruments can be enabled without restarting the server if you use the
UPDATE statement, however not all of the
instruments will be active until a restart. See the MySQL documentation for more information about these instruments.
Why are my query samples truncated?
By default, we limit the length of captured query samples to 4096 bytes. If your queries are longer than this length,
you can contact VividCortex Customer Support to have this lengthened, or you can use a VividCortex config file
and use the option
If your queries are being truncated and they are smaller than the
max-sample-length and you are using the Off-Host configuration, it is likely that MySQL or PostgreSQL is shortening the queries in
Both MySQL and PostgreSQL truncate queries at 1024 characters by default. For MySQL, you can change this value using the
performance_schema_max_sql_text_length variable in version 5.7.6 (and later). For PostgreSQL, use the
Why am I not seeing query samples?
In on-host installations, the most common reason for not seeing query samples is either that they are either disabled for some or all of your hosts by your administrator, or you are logged in as a user without proper permissions to view query samples; Read-Write permissions are required for customers using RBAC. We will also be unable to capture prepared statements which are executed as part of a long-running connection.
In off-host configurations, the most common reasons are not having
pg_stat_activity (PostgreSQL) enabled and collecting query data, or that the VividCortex user does not
have sufficient permissions to access that data.
We are also unable to collect query samples for prepared statements for MySQL (as query samples are not made available
by the database). PostgreSQL does not provide query samples with the literals included, so we do not show
this text as it is identical to the query digest.
Lastly, query samples may be disabled for some or all of your hosts by your account administrator.
Why are some queries not displaying EXPLAIN plans?
We need query samples in order to see EXPLAIN plans, so first ensure you are collecting query samples (above) for the queries you want to have EXPLAINed.
If you have query samples, we will not collect EXPLAIN plans for queries which could cause unpredictable load to the server during an EXPLAIN, such queries containing a sub-query. The VividCortex user connecting to the database also needs the proper permissions to execute EXPLAIN.
Lastly, EXPLAIN plans can be disabled by your account administrator.
Why are some of my PostgreSQL queries displaying
Typically this occurs when the user VividCortex is connecting to the database with does not have
SUPERUSER privilege or the
rds_superuser role. In this case,
will typically appear as much or most of the query volume. You can read more about the required
database privileges here.
However, some query volume for hosted PostgreSQL instances on Amazon, such as RDS and Heroku, will always display as
due to Amazon using a custom user (such as
rdsadmin) to perform monitoring and maintenance functions, including
fetching CloudWatch metrics. The queries being run are not viewable by any user, including users
who have been assigned the
rds_superuser role. The same applies to Heroku, where an application (“Dyno”)
gets a dedicated user and database assigned to it, but one that shares the host server with other applications’
How does VividCortex compute query latency?
For clients monitoring their database locally, query latency is calculated as the time between receiving the last byte of the request and receiving the first byte of the response. For clients monitoring remotely, latency is fetched directly from the database’s own statistics tables (either pg_stat_activity or the performance_schema).
Why does the latency for some queries in VividCortex not match the MySQL slow query log?
If monitoring locally, latency will include any delay due to network effects. Additionally, the MySQL slow query log does not include time spent waiting for any initial locks.
How can I export data from VividCortex?
Premium customers have access to the VividCortex API, which will allow you to fetch any data we collect. Contact your Account Manager or Customer Support if you would like more information about the API or the Premium features.
If I delete a host, will the old data remain available?
Yes. All data collected remains available even if you delete a host. The host and its data will be shown if you select a time range where that host has data.
How do I move a host from one environment to another?
See our documentation here.
What’s the difference between Queries and Processlist/Stat Activity/CurrentOp Queries?
In the Profiler, “Queries” data comes from either decoding TCP traffic (for local installations), pg_stat_statements (remote PostgreSQL), or performance_schema (remote MySQL). This view includes all queries executed on your server.
The other options are …
|Category||Description||Can be ranked by…|
|MySQL Processlist Queries||Query digest data captured from the
||Count, Locks, Total Time|
|PostgreSQL Activity||Query digest data captured from
||Count, Locks, Total Time|
|MongoDB Current Op Queries||Queries captured from the
||Blocked, Count, Total Time|
Those tables are queried once per second. This view of the data is very useful to see what activity your database is performing at a given point in time.
How do I search for a specific query?
See the section “Query Searching” in the Profiler documentation.
How do I see what MySQL warnings were associated with a query?
MySQL warnings are generally only visible to the user who issued the query. However, for SELECT statements, we can see the warning associated with a specific query sample.
Learn more about warnings in our documentation here.
How do I control what query samples are sent to VividCortex?
For information about how to control the query data sent to VividCortex, see our documentation on query samples here.
How do I access the API?
API access is a Premium level feature. Contact Customer Support if you would like more information.
How do I use a local proxy with VividCortex?
Information about using a proxy can be found in our Configuration documentation.
How do I start / stop the VividCortex service?
See Starting and Stopping VividCortex in our documentation.
How are licenses used? How many do I have?
Each database and its associated monitoring operating system (whether remote or local) consumes one license. Any operating system instances which do not monitor a database also consume one license. You can see the number of licenses you are currently using, and the number that your organization has available for use, on the Settings page under Organization Overview.
How do I view the agent’s log?
You can view the agent logs in /var/log/vividcortex. Alternatively, you can use the Agents Dashboard to view logs within the VividCortex app.
How do I rename or delete an environment?
To rename or delete an environment, go to Settings, then under Organization Settings select “Environments.” From there you will have the option to edit an environment’s name by picking the pencil icon, or delete the environment by clicking the trashcan.