I have an application running CockroachDB on AWS and want to log all of the queries it executes. However, I can’t find anything in my cluster’s logs that seems to contain the queries. I tried grepping through them for my application’s SELECT statements but can’t find them.
Is there a way to enable query logging?
The other answer is outdated. There are two mechanisms:
for regular inspection/troubleshooting, one should use SQL statement execution logging as documented here: https://www.cockroachlabs.com/docs/stable/query-behavior-troubleshooting.html#cluster-wide-execution-logs
for access audits (when required for e.g. regulation) use audit logging: https://www.cockroachlabs.com/docs/stable/sql-audit-logging.html
When starting a node with cockroach start, include the --vmodule=executor=2 flag to log all SQL queries. For example:
cockroach start --background --vmodule=executor=2
You can access the logs then from the log files stored in cockroach-data/logs
If you’re curious about logging queries that run “too long”, set the env var COCKROACH_TRACE_SQL to a duration to log all queries longer than that duration.
One can also activate this logging after starting the server by accessing the URL http://[admin UI URL]/debug/vmodule/executor=2 using the same host/port as the admin UI.
Related
If want to see, all the ran queries, from Kibana Dev tool, how to see it? Is there any query, which shows all the ran queries may be for last 30 days?
I guess there is no Api for showing history of executed queries how ever you can find the related log files in var/log/elasticsearch file path More over if you want to always keep record of all executed queries and events in your Dev tools you can create and index for it and use Logstash to insert your operation logs(which previously said where is stored) into that index.
I'm seeing an error with some Laravel code that uses an AWS RDS database. The code writes a record to the database and then immediately does a search to load that record using the primary key and gets no results.
If I try it manually afterwards I find the record. If I insert a 1-second sleep in the code it works correctly.
I've tried this using Laravel's separate settings for read and write hosts. I've also tried setting them to the same host and only using one host. The result is always the same. However other environments with the same configuration do not have the error.
Is there an option in RDS that needs to be changed to have the record available immediately after it's written.
The error is due to the mySQL master-slave replication lag.
A common mistake is to use a mySQL cluster and then perform a read
immediately after a write.
Since the read occurs on one of the slave/read hosts and the write occurs on the master, the data would not be replicated at the time of the read.
There are a couple of ways to rectify the error:
The read immediately after must be performed on the master (not the slave). Even though you've mentioned that you changed it to a single host, often people make a mistake while switching the connection. Refer this SO post to properly switch connections in Laravel
An easier way may be to use the sticky database option in Laravel. Beware: this may cause performance issues if not used carefully for only the use case you desire. From the docs:
The sticky option is an optional value that can be used to allow the
immediate reading of records that have been written to the database
during the current request cycle.
If the sticky option is enabled and a "write" operation has been
performed against the database during the current request cycle, any
further "read" operations will use the "write" connection.
The most "non-obvious" way is to NOT perform a read immediately after a write. Think about whether this can be avoided depending on your use case.
Other methods: refer this SO post
I have a clarion application running in Win Server 2016 talking to a sybase DB, over the past few weeks we find the application gets frozen for different users at a given time. However the user can leave the session as such and start a new one and that works good. The users are known to use multiple instances of the same application in one remote server or on multiple servers. Having said that, I wanted to get more information on the freezeup and looked through the application event logs in the system where I see explorer.exe crashes but these correlate to the time of occurrence of the issue at certain times but not always, checked the DB transaction logs from Sybase and I do not find any crashes, errors or stuck connections. Having said that, since I have exhausted all possible options I am reaching out to you guys to know if there are any other places that i can look for to gather more information.
I would love to know of any application / tools that we could use to gather logs of a frozen clarion application on windows. Also good to know if anyone has faced such a situation and where and how have you guys looked into the issue.
Thanks in advance for your help in this.
Clarion's runtime library and database drivers expect a persistent connection. Disconnects that are normal with remote ODBC can cause a problem (including app hangs) unless you test for them at the ABC file mgr level and reconnect, or use similar steps to test and recover.
If you're looking for specifics about what's going on between the driver and the SQL backend, I suggest using Clarion's database driver trace facilities. From the help topic: "Logging Driver I/O for debugging":
To view the trace details in debugview, name the target trace file "DEBUG:"
Logging opens the named logfile for exclusive access. If the file exists, the new log data is appended to the file.
On Demand Logging
For on-demand logging you can use property syntax within your program to conditionally turn various levels of logging on and off. The logging is effective for the target table and any view for which the target table is the primary table.
file{PROP:Profile}=Pathname !Turns Clarion I/O logging on
file{PROP:Profile}="DEBUG:" !Turns Clarion I/O logging on and
!sends output via OutputDebugString()
!(viewable via debugview, etc)
file{PROP:Profile}='' !Turns Clarion I/O logging off
PathName = file{PROP:Profile} !Queries the name of the log file
file{PROP:Log}=string !Writes the string to the log file
file{PROP:Log}="DEBUG:" !Writes the string to the log file
file{PROP:Details}=1 !Turns Record Buffer logging on
fFile{PROP:Details}=0 !Turns Record Buffer logging off
where Pathname is the full pathname or the filename of the log file to create. If you do not specify a path, the driver writes the log file to the current directory.
You can also accomplish on demand logging with a SEND() command and the LOGFILE driver string. See LOGFILE for more information.
Example I use frequently, which was based on the help above:
SYSTEM{PROP:DriverTracing} = '1'
CRMNotes{PROP:TraceFile} = 'DEBUG:'
CRMNotes{PROP:Details}=1
CRMNotes{PROP:Profile}= 'DEBUG:'
CRMNotes{PROP:LogSQL} = 1
I have installed OEM 13c and deployed a couple of agents and want to test out the Log File Monitoring utility. I have enabled it and added a log file to monitor.
When I go and test it out, it does not show any alerts when they are put into the Log File. On the agent server, I have tailed the file and see the messages coming into the log file.
Does anyone have experience adding log files to OEM? I could have configured it wrong. Or is there any troubleshooting steps that I can follow to see if the server is even contacting the agent for reading the log file. Status of the agent is good with no incidents.
Without access to the system, it would be difficult to tell you the exact cause of this issue. However, I can list a few potential causes of this issue that I have experienced personally:
Permissions. The Oracle Enterprise Manager Agent is very convoluted when it comes to system permissions within a remote server. The agent can be owned and run as any number of users but during metric evaluation, may also need sudo or pam-authentication permissions to access certain entities on the server. Depending on the authentication profiles on that server, this could be the cause of your issue. There are ways to grant the agent access through the PAM stack if that is necessary.
Syntax. The wildcard syntax in the OEM GUI can be a little confusing as well. I would play with the wildcard elements a bit on the "String" component to ensure that it isn't as simple as adding wildcards to the beginning and end of the string. Without diving into the binaries of the agent plugins, it is difficult to assess exactly how the agent is evaluating this particular metric
One suggestion I would have is to go through the agent commands. There are specific commands you can run to manually force an agent to evaluate a particular metric for a particular target. This can allow you to manually trigger the metric collection locally on the server and evaluate what exactly is being performed at the agent level.
On the system I was running (12c) the command was as follows:
emctl control agent runCollection <hostname>:host host_storage
I am quite new for log4j2 logger and my requirement to write a log from application server and web server.
I am having two different environment on which J BOSS server is deployed.
Now I am having a log file on web server environment which is writing logs for errors and I want to write logs from application server also in same file.
Please suggest.
If you want the logs to be integrated together you should use a solution like Splunk or Elastic Search/Logstash/Kibana (ELK).
When you try to write to a file from 2 different processes your file will get corrupted unless you use file locking. However, your throughput will decrease significantly and it isn't supported for rolling files. So the best approach is to send the logs to a single process where they can be aggregated.