[Bug]: Servers appear stale or offline, but are in fact online and working

[CRPrinzler]

Bug description

It seems as if the netdata agent dies unexspected and does not recover. If the netdata process is monitored and automatically restarted with systemctl restart netdata, the server again appears as online in the dashboard.

This produces false "server unreachable" alerts.

Expected behavior

Netdata agent should never stop by itself.

Steps to reproduce

1. Install the netdata agent via the dashboard supplied script without any modifications.

Installation method

kickstart.sh

System info

Linux target 5.4.0-105-generic #119-Ubuntu SMP Mon Mar 7 18:49:24 UTC 2022 x86_64 x86_64 x86_64 GNU/Linux
/etc/lsb-release:DISTRIB_ID=Ubuntu
/etc/lsb-release:DISTRIB_RELEASE=20.04
/etc/lsb-release:DISTRIB_CODENAME=focal
/etc/lsb-release:DISTRIB_DESCRIPTION="Ubuntu 20.04.6 LTS"
/etc/os-release:NAME="Ubuntu"
/etc/os-release:VERSION="20.04.6 LTS (Focal Fossa)"
/etc/os-release:ID=ubuntu
/etc/os-release:ID_LIKE=debian
/etc/os-release:PRETTY_NAME="Ubuntu 20.04.6 LTS"
/etc/os-release:VERSION_ID="20.04"
/etc/os-release:VERSION_CODENAME=focal
/etc/os-release:UBUNTU_CODENAME=focal

Netdata build info

Packaging:
    Netdata Version ____________________________________________ : v1.44.3
    Installation Type __________________________________________ : kickstart-static
    Package Architecture _______________________________________ : x86_64
    Package Distro _____________________________________________ : unknown
    Configure Options __________________________________________ :  '--prefix=/opt/netdata/usr' '--sysconfdir=/opt/netdata/etc' '--localstatedir=/opt/netdata/var' '--libexecdir=/opt/netdata/usr/libexec' '--libdir=/opt/netdata/usr/lib' '--with-math' '--with-user=netdata' '--disable-exporting-mongodb' '--enable-cloud' '--without-bundled-protobuf' '--disable-dependency-tracking' '--enable-lto' 'CFLAGS=-ffunction-sections -fdata-sections -static -O2 -funroll-loops -I/openssl-static/include -I/libnetfilter-acct-static/include/libnetfilter_acct -I/curl-local/include/curl -I/usr/include/libmnl -pipe' 'LDFLAGS=-Wl,--gc-sections -static -L/openssl-static/lib64 -L/libnetfilter-acct-static/lib -lnetfilter_acct -L/usr/lib -lmnl -L/usr/lib -lzstd -L/curl-local/lib' 'PKG_CONFIG=pkg-config --static' 'PKG_CONFIG_PATH=/openssl-static/lib64/pkgconfig:/libnetfilter-acct-static/lib/pkgconfig:/usr/lib/pkgconfig:/curl-local/lib/pkgconfig'
Default Directories:
    User Configurations ________________________________________ : /opt/netdata/etc/netdata
    Stock Configurations _______________________________________ : /opt/netdata/usr/lib/netdata/conf.d
    Ephemeral Databases (metrics data, metadata) _______________ : /opt/netdata/var/cache/netdata
    Permanent Databases ________________________________________ : /opt/netdata/var/lib/netdata
    Plugins ____________________________________________________ : /opt/netdata/usr/libexec/netdata/plugins.d
    Static Web Files ___________________________________________ : /opt/netdata/usr/share/netdata/web
    Log Files __________________________________________________ : /opt/netdata/var/log/netdata
    Lock Files _________________________________________________ : /opt/netdata/var/lib/netdata/lock
    Home _______________________________________________________ : /opt/netdata/var/lib/netdata
Operating System:
    Kernel _____________________________________________________ : Linux
    Kernel Version _____________________________________________ : 5.4.0-105-generic
    Operating System ___________________________________________ : Ubuntu
    Operating System ID ________________________________________ : ubuntu
    Operating System ID Like ___________________________________ : debian
    Operating System Version ___________________________________ : 20.04.6 LTS (Focal Fossa)
    Operating System Version ID ________________________________ : none
    Detection __________________________________________________ : /etc/os-release
Hardware:
    CPU Cores __________________________________________________ : 4
    CPU Frequency ______________________________________________ : 3400000000
    RAM Bytes __________________________________________________ : 16629256192
    Disk Capacity ______________________________________________ : 5000991916032
    CPU Architecture ___________________________________________ : x86_64
    Virtualization Technology __________________________________ : none
    Virtualization Detection ___________________________________ : systemd-detect-virt
Container:
    Container __________________________________________________ : none
    Container Detection ________________________________________ : systemd-detect-virt
    Container Orchestrator _____________________________________ : none
    Container Operating System _________________________________ : none
    Container Operating System ID ______________________________ : none
    Container Operating System ID Like _________________________ : none
    Container Operating System Version _________________________ : none
    Container Operating System Version ID ______________________ : none
    Container Operating System Detection _______________________ : none
Features:
    Built For __________________________________________________ : Linux
    Netdata Cloud ______________________________________________ : YES
    Health (trigger alerts and send notifications) _____________ : YES
    Streaming (stream metrics to parent Netdata servers) _______ : YES
    Back-filling (of higher database tiers) ____________________ : YES
    Replication (fill the gaps of parent Netdata servers) ______ : YES
    Streaming and Replication Compression ______________________ : YES (zstd lz4 gzip)
    Contexts (index all active and archived metrics) ___________ : YES
    Tiering (multiple dbs with different metrics resolution) ___ : YES (5)
    Machine Learning ___________________________________________ : YES
Database Engines:
    dbengine ___________________________________________________ : YES
    alloc ______________________________________________________ : YES
    ram ________________________________________________________ : YES
    map ________________________________________________________ : YES
    save _______________________________________________________ : YES
    none _______________________________________________________ : YES
Connectivity Capabilities:
    ACLK (Agent-Cloud Link: MQTT over WebSockets over TLS) _____ : YES
    static (Netdata internal web server) _______________________ : YES
    h2o (web server) ___________________________________________ : YES
    WebRTC (experimental) ______________________________________ : NO
    Native HTTPS (TLS Support) _________________________________ : YES
    TLS Host Verification ______________________________________ : YES
Libraries:
    LZ4 (extremely fast lossless compression algorithm) ________ : YES
    ZSTD (fast, lossless compression algorithm) ________________ : YES
    zlib (lossless data-compression library) ___________________ : YES
    Judy (high-performance dynamic arrays and hashtables) ______ : YES (bundled)
    dlib (robust machine learning toolkit) _____________________ : YES (bundled)
    protobuf (platform-neutral data serialization protocol) ____ : YES (system)
    OpenSSL (cryptography) _____________________________________ : YES
    libdatachannel (stand-alone WebRTC data channels) __________ : NO
    JSON-C (lightweight JSON manipulation) _____________________ : YES
    libcap (Linux capabilities system operations) ______________ : NO
    libcrypto (cryptographic functions) ________________________ : YES
    libm (mathematical functions) ______________________________ : YES
    jemalloc ___________________________________________________ : NO
    TCMalloc ___________________________________________________ : NO
Plugins:
    apps (monitor processes) ___________________________________ : YES
    cgroups (monitor containers and VMs) _______________________ : YES
    cgroup-network (associate interfaces to CGROUPS) ___________ : YES
    proc (monitor Linux systems) _______________________________ : YES
    tc (monitor Linux network QoS) _____________________________ : YES
    diskspace (monitor Linux mount points) _____________________ : YES
    freebsd (monitor FreeBSD systems) __________________________ : NO
    macos (monitor MacOS systems) ______________________________ : NO
    statsd (collect custom application metrics) ________________ : YES
    timex (check system clock synchronization) _________________ : YES
    idlejitter (check system latency and jitter) _______________ : YES
    bash (support shell data collection jobs - charts.d) _______ : YES
    debugfs (kernel debugging metrics) _________________________ : YES
    cups (monitor printers and print jobs) _____________________ : NO
    ebpf (monitor system calls) ________________________________ : YES
    freeipmi (monitor enterprise server H/W) ___________________ : NO
    nfacct (gather netfilter accounting) _______________________ : YES
    perf (collect kernel performance events) ___________________ : YES
    slabinfo (monitor kernel object caching) ___________________ : YES
    Xen ________________________________________________________ : NO
    Xen VBD Error Tracking _____________________________________ : NO
    Logs Management ____________________________________________ : YES
Exporters:
    AWS Kinesis ________________________________________________ : NO
    GCP PubSub _________________________________________________ : NO
    MongoDB ____________________________________________________ : NO
    Prometheus (OpenMetrics) Exporter __________________________ : YES
    Prometheus Remote Write ____________________________________ : YES
    Graphite ___________________________________________________ : YES
    Graphite HTTP / HTTPS ______________________________________ : YES
    JSON _______________________________________________________ : YES
    JSON HTTP / HTTPS __________________________________________ : YES
    OpenTSDB ___________________________________________________ : YES
    OpenTSDB HTTP / HTTPS ______________________________________ : YES
    All Metrics API ____________________________________________ : YES
    Shell (use metrics in shell scripts) _______________________ : YES
Debug/Developer Features:
    Trace All Netdata Allocations (with charts) ________________ : NO
    Developer Mode (more runtime checks, slower) _______________ : NO

Additional info

No response

[hugovalente-pm]

@CRPrinzler to confirm on this case, the issue you are reporting is this? "netdata agent dies unexspected and does not recover." the bug title mentions "Servers appear stale or offline, but are in fact online and working" which based on the discussion on Discord was sorted with restarting the agent but this is after they had died unexpectedly?

On the, reachability notifications being triggered this is an after-effect of the above right?

[CRPrinzler]

it just seems weird because netdata agent seems to lose all connection and vanishes. System Status monitor, which I have set up, then automatically restarts via systemctl restart netdata.

[hugovalente-pm]

@CRPrinzler could you look into the logs when this happens and see if something there could help give some hint into what is happening? also, would it be possible to test this on the latest stable version v1.45.1? there have been a lot of bug fixes released

[hugovalente-pm]

@CRPrinzler were you able to try this using the latest stable version?