I'm new to Loopback. I have used Sequelize ORM in the past, and I'm used to seeing Sequelize output the SQL statements to the Console. How can I do the same with Loopback 4? I've done extensive searching on the web, and I found a place where they suggested to add debug: true to the datasource config json file. However, this change had no effect.
Any help is greatly appreciated.
Hello from the LoopBack team 👋
We use debug module to deal with debug logging and most connectors print SQL statements in their debug log.
You can enable debug logs by setting the environment variable DEBUG. For example, on a Unix system (Unix, MacOS), you can run the following command:
DEBUG=loopback:connector* npm start
On Windows, you have to set the variable in a standalone command.
set DEBUG=loopback:connector*
npm start
Related
I have a Django project connecting to a PostgreSQL database which I develop in PyCharm, and I want to enable PostgreSQL history logging.
There is PSQL_HISTORY env variable set to /home/user/apps/postgres/logs/.pycharm_log, but when I start the project in PyCharm and update some data via the Django Admin (which certainly hits the database) -- nothing gets logged and the file is not created at all.
Is there a way to make PyCharm and PSQL_HISTORY work together as I expected?
'psql' is the name of a specific client tool. Why would a completely different tool use psql's configuration options? If you want to log every statement sent to the server, you could configure that in the server side with log_statement=all.
I am using a Windows Machine to connect to a remote DB2 instance. Ran into this issue
SQL1531N The connection failed because the name specified with the DSN connection string keyword could not be found in either the db2dsdriver.cfg configuration file or the db2.cli.ini configuration file. Data source name specified in the connection string: <DSN>
I have configured ODBC Data source using ODBC Data Source Administrator it has connected successfully.
Upon further investigation, I am unable to locate db2dsdriver.cfg on IBM DATA SERVER DRIVER folder. I am able to find db2dsdriver.lvl and dbs2dsdriver.xds. Just not the .cfg file. I am also unsure where HammerDB looks for the config file.
I have looked at the configuration of DB2 from the website but I am unable to get any useful information from there. https://www.hammerdb.com/docs/ch04s02.html
For the tiny footprint ODBC and CLI driver (known as clidriver) from IBM, you are responsible for creating and editing the db2dsdriver.cfg configuration file. It is a small XML file documented here and in related linked pages. The hammerdb documentation also gives a minimal example and you linked to this page in your question.
You can create and edit this file either by command lines to the db2cli tool, or by directly editing with a text editor (or XML editor). It may be easier to use an editor than to learn the command lines, although command lines have the advantage that they lend themselves to scripting this activity for larger installations.
On Microsoft-Windows you can also use Notepad to create and edit the file db2dsdriver.cfg.
An important step is that following editing of the file you must first validate its contents before trying any database connections. Validation checks that the syntax of the XML in the file is correct. To validate, you use the db2cli validate command described here. It must show a successful result before you try to connect to any database. Once validation completes without errors, you can also use db2cli validate -connect -dsn XXX -user YYY -passwd ZZZ to test the connection independently of your application (in this case hammerdb). Once you get a successful connection with the db2cli validate -connect -dsn ... then your application (hammerdb) will connect correctly.
There are many examples of db2dsdriver.cfg contents online , but your first source should be the Db2 Knowledge Centre online, which details the command line options to the db2cli command, along with giving examples of db2dsdriver.cfg.
If you already have a working Db2 configuration with local and remote databases (but no db2dsdriver.cfg file), you can also use a tool db2dsdcfgfill to populate db2dsdriver.cfg from your existing Db2 configuration. See docs here.
I am trying to create a new Strapi app on Ubuntu 16.4 using MongoDB. After stepping through the tutorial, here: https://strapi.io/documentation/3.0.0-beta.x/guides/databases.html#mongodb-installation, I get the following error: Connection test failed: spawn npm; ENOENT
The error seems obvious, but I'm having issues getting to the cause of it. I've installed latest version of MongoDB and have ensured it is running using service mongod status. I can also connect directly using nc, like below.
$ nc -zvv localhost 27017
Connection to localhost 27017 port [tcp/*] succeeded!
Here is an image of the terminal output:
Any help troubleshooting this would be appreciated! Does Strapi perhaps log setup errors somewhere, or is there a way to get verbose logging? Is it possible the connection error would be logged by MongoDB somewhere?
I was able to find the answer. The problem was with using npx instead of Yarn. Strapi documentation states that either should work, however, it is clear from my experience that there is a bug when using npx.
I switched to Yarn and the process proceeded as expected without error. Steps were otherwise exactly the same.
Update: There is also a typo in Strapi documentation for yarn. They include the word "new" before the project name, which will create a project called new and ignore the project name.
Strapi docs (incorrect):
yarn create strapi-app new my-project
Correct usage, based on my experience:
yarn create strapi-app my-project
The ENOENT error is "an abbreviation of Error NO ENTry (or Error NO ENTity), and can actually be used for more than files/directories."
Why does ENOENT mean "No such file or directory"?
Everything I've read on this points toward issues with environment variables and the process.env.PATH.
"NOTE: This error is almost always caused because the command does not exist, because the working directory does not exist, or from a windows-only bug."
How do I debug "Error: spawn ENOENT" on node.js?
If you take the function that Jiaji Zhou provides in the link above and paste it into the top of your config/functions/bootstrap.js file (above module.exports), it might give you a better idea of where the error is occurring, specifically it should tell you the command it ran. Then run the command > which nameOfCommand to see what file path it returns.
"miss-installed programs are the most common cause for a not found command. Refer to each command documentation if needed and install it." - laconbass (from the same link, below Jiaji Zhou's answer)
This is how I interpret all of the above and form a solution. Put that function in bootstrap.js, then take the command returned from the function and run > which nameOfCommand. Then in bootstrap.js (you can comment out the function), put console.log(process.env.PATH) which will return a string of all the directories your current environment is checking for executables. If the path returned from your which command isn't in your process.env.PATH, you can move the command into a path, or try re-installing.
I am using helios Eclipse for debugging my code in postgresql.
My aim is to know how postgresql uses join algorithms during the join query, so I started to debug nodenestloop.c which is in the Executor folder.
I gave break points in that file, But whenever I try to debug that file, the control goes to main.c and never comes back,How do I constraint the control only to that particular file(nodenestloop.c)
Below are the following fields which I gave in Debug configurations of Helios Eclipse.
C/C++ Application - src/backend/postgres and
project - pgsql
I followed the steps given in the following link for running the program.
https://wiki.postgresql.org/wiki/Working_with_Eclipse#
I even uncheked the field "Start on Start up=main" , but When I do that, The step in and Step over buttons are not activated and the following problem has popped up.
Could not save master table to file '/home/ravi/workspace/.metadata/.plugins/org.eclipse.core.resources/.safetable/org.eclipse.core.resources'.
/home/ravi/workspace/.metadata/.plugins/org.eclipse.core.resources/.safetable/org.eclipse.core.resources (Permission denied)
So I started eclipse using sudo, but this time the following error has come in the console of eclipse.
"root" execution of the PostgreSQL server is not permitted.
The server must be started under an unprivileged user ID to prevent
possible system security compromise. See the documentation for
more information on how to properly start the server.
Could any one help me with this.
Thank you
Problem 1: User ID mismatch
Reading between the lines, it sounds like you're trying to debug a PostgreSQL instance that's running as the postgres user, or a different user ID to your own anyway. Hence your attempt to use sudo.
That's painful, especially when using an IDE like Eclipse. With plain gdb you can just sudo the gdb command to the desired uid, e.g. sudo -u postgres -p 12345 to attach to pid 12345 running as user postgres. This will not work with Eclipse. In fact, running it with sudo has probably left your workspace with some messed up file permissions; run:
sudo chown -R ravi /home/ravi/workspace/
to fix file ownership.
If you want to debug processes under other user IDs with Eclipse, you'll need to figure out how to make Eclipse run gdb with sudo. Do not just run all of Eclipse with sudo.
Problem 2: Trying to run PostgreSQL under the control of Eclipse
This:
"root" execution of the PostgreSQL server is not permitted. The server must be started under an unprivileged user ID to prevent possible system security compromise. See the documentation for more information on how to properly start the server.
suggests that you're also attempting to let Eclipse start postgres directly. That's very useful if you're trying to debug the postmaster, but since you're talking about the query planner it's clear you want to debug a particular backend. Launching the postmaster under Eclipse is useless for that, you'll be attached to the wrong process.
I think you probably need to read the documentation on PostgreSQL's internals:
Tour of PostgreSQL Internals
PostgreSQL internals through pictures
Documentation chapter - internals
Doing it right
Here's what you need to do - rough outline, since I've only used Eclipse for Java development and do my C development with vim and gdb:
Compile a debug build of PostgreSQL (compiled with ./configure --enable-debug and preferably also CFLAGS="-ggdb -Og -fno-omit-frame-pointer"). Specify a --prefix within your homedir, like --prefix=$HOME/postgres-debug
Put your debug build's bin directory first on your PATH, e.g. export PATH=$HOME/postgres-debug/bin:$PATH
initdb -U postgres -D $HOME/postgres-debug-data a new instance of PostgreSQL from your debug build
Start the new instance with PGPORT=5599 pg_ctl -D $HOME/postgres-debug-data -l $HOME/postgres-debug-data.log -w start
Connect with PGPORT=5599 psql postgres
Do whatever setup you need to do
Get the backend process ID with SELECT pg_backend_pid() in a psql session. Leave that session open; it's the one you'll be debugging.
Attach Eclipse's debugger to that process ID, using the Eclipse project that contains the PostgreSQL extension source code you're debugging. Make sure Eclipse is configured so it can find the PostgreSQL source code you compiled with too (no idea how to do that, see the manual).
Set any desired breakpoints and resume execution
In the psql session, do whatever you need to do to make your extension run and hit the breakpoint
When execution pauses at the breakpoint in Eclipse, debug as desired.
Basic misunderstandings?
Also, in case you're really confused about how all this works: PostgreSQL is a client/server application. If you are attempting to debug a client program that uses libpq or odbc, and expecting a breakpoint to trigger in some PostgreSQL backend extension code, that is not going to happen. The client application communicates with PostgreSQL over a TCP/IP socket. It's a separate program. gdb cannot set breakpoints in the PostgreSQL server when it's connected to the client, because they are separate programs. If you want to debug the server, you have to attach gdb to the server. PostgreSQL uses one process per connection, so you have to attach gdb to the correct server process. Which is why I said to use SELECT pg_backend_pid() above, and attach to the process ID.
See the internals documentation linked above, and:
PostgreSQL site - coding
PostgreSQL wiki - developer resources
Developer FAQ
Attaching gdb to a backend on linux/bsd/unix
I also faced similar issue and resolved it after some struggle
I misunderstood the following point under Debugging with child processes in the wiki (https://wiki.postgresql.org/wiki/Working_with_Eclipse).
5."Start postmaster & one instant of postgresql client (for creating one new postgres)"
The above step should be performed from terminal by starting postgres server and one client.
Hope this helps
Once this is done then debugger in eclipse needs to be started for C/C++ Attach to Application
I am trying to access an Oracle ILOM interface via command line to read the event log.
As far as I know there are several ways to do this, but none work for me and my environment:
IPMItools: seems to be available only for Linux or on the CD/DVD that originally came with the server, which of course was lost;
SSH access (via putty) works fine, but I could not figure a way to automate logging in, running a command on the remote server and reading the result (still looking into it);
command line SSH access via plink works fine, but as soon as I try adding a command to run on the server (e.g. plink.exe -l root -pw password FQDN help) I get the error message "shell: Invalid credentials". adding the -t option did not change anything;
the SSH.NET library for powershell fails with the following exception "Exception calling "Connect" with "0" argument(s): "No suitable authentication method found to complete authentication". Documentation suggests adding a generated public RSA key to the server to allow for possword-less login. That cannot be done on Sun ILOMs;
Connecting via a serial port as detailed here does not work for me. I must be missing something from the posted code, but I simply cannot open a connection.
Has anyone ever tried to access an ILOM from command line? Could anyone offer a pointer as to what might work?
Ideally I'd like to automate this in a powershell script to be run from a Windows machine, but I'm open to any suggestions that do not require Visual Studio to implement.
Any help would be greatly appreciated!
ipmi and ssh remote command only supports in ilom3.0+.
if you are using alom, ilom2.0, or sxcf, you won't be able to use these tools.
I'd recommand to use python with pexpect https://pexpect.readthedocs.io/en/stable/.
check my snippet https://gist.github.com/happlebao/ca143cf3feaf60ca8ef75f7a66cf8a8a