"section 'db' is not used."

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1

Hi,
Having installed netdata 1.33.1-2 on my openwrt router, I wanted to extend my history. So, I added the following snippet, which I’d found in the netdata documentation, to /etc/netdata/netdata.conf:

[db]
    mode = dbengine

    # per second data collection
    update every = 1

    # number of tiers used (1 to 5, 3 being default)
    storage tiers = 3

    # Tier 0, per second data
    dbengine multihost disk space MB = 256

    # Tier 1, per minute data
    dbengine tier 1 multihost disk space MB = 128
    dbengine tier 1 update every iterations = 60

    # Tier 2, per hour data
    dbengine tier 2 multihost disk space MB = 64
    dbengine tier 2 update every iterations = 60

After restarting the netdata service, however, I noticed no change after a few days. I still had the same short window of statistical data.

Having googled around a bit, I discovered I could access http://<router_ip>:19999/netdata.conf in order to see the active configuration. In this, I found:


# per chart configuration

# section 'db' is not used.
[db]
	mode = dbengine
	update every = 1
	storage tiers = 3

Why is the section 'db' not used ? How can I get netdata to respect /etc/netdata/netdata.conf?

2

Hi, @kopf. 1.33.1-2 is old, the latest stable is 1.38.1.

3

Hi @ilyam8 ,

Unfortunately 1.33.1-2 is the newest version available to be installed on openwrt. I see from github that 1.33.1 was released about a year ago, which is, for me at least, a tolerable age.

Has the method for configuring long-term metric retention changed in the intervening releases? Or, more importantly, can I find the documentation for 1.33.1 somewhere so I can look up the corresponding entry for https://learn.netdata.cloud/docs/deployment-in-production/metric-retention---database/change-how-long-netdata-stores-metrics ?

Thanks!

4

Yes, there was a huge amount of changes, and dbengine (metrics storing engine) was rewritten. You can use GitHub to read old documentation, see v1.33.1 tag dbengine readme.

5

Ah, thanks for the info! In that case it’s a pity that I can’t install the latest version, but hey.

I’ve added the options (memory mode and dbengine (multihost) disk space). Unfortunately the disk space config option is ignored, no matter whether I use “dbengine multihost disk space” or “dbengine disk space”:

# global netdata configuration

[global]
	update every = 2
	memory deduplication (ksm) = no
	debug log = syslog
	error log = syslog
	access log = none
	run as user = root
	memory mode = dbengine

	# option 'dbengine disk space' is not used.
	dbengine disk space = 64000

Any ideas?

6

Both of these options are supported in v1.33.1. Probably your Netdata compiled without dbengine support, check netdata -W buildinfo.

7

Bingo! Sorry, I was unaware that this was possible.

OK, time to have a look into compiling my own netdata for ARM. Thanks for your help!

8

Hi @kopf,

We have a ticket open for having the install script to support OpenWRT builds: https://github.com/netdata/netdata/issues/9517. Because of this discussion, Austin has raised a PR for the final bit to close it. That should make it a lot easier for you to get going.

9

That’s awesome news! Glad this message board thread wasn’t to no avail after all :slight_smile:

I’m following the github issue now - if I can help in any way, let me know.