{{indexmenu_n>2}}
====== Components and indicators ======

===== Monitoring coverage =====

<mermaid>
flowchart LR
    EXP["fast-epdg<br/>/metrics :9817"]

    EXP --> CFG["Config<br/>2 metrics"]
    EXP --> NET["Network<br/>1 metric"]
    EXP --> PROTO["Protocols L5-L7<br/>15 metrics"]
    EXP --> SVC["Service KPI<br/>4 metrics"]
    EXP --> SESS["Session State<br/>4 metrics"]
    EXP --> APP["Application<br/>3 metrics"]
    EXP --> SYS["System<br/>4 metrics"]

    PROTO --> IKEV2["IKEv2<br/>SWu — 3"]
    PROTO --> GTPC["GTPv2-C<br/>S2b — 4"]
    PROTO --> GTPU["GTP-U<br/>S2b data — 3"]
    PROTO --> DIA["Diameter<br/>SWm/SWx/S6b — 5"]
</mermaid>

===== Quantitative review by category =====

^ Category                    ^ Number of metrics  ^ Survey interval  ^ Key indicators                                                                                  ^
| **Config**                  | 2                  | 10 sec           | Configuration status, reload counter                                                            |
| **Network**                 | 1                  | 10 sec           | Node connection status (PGW/AAA/HSS)                                                            |
| **IKEv2 (SWu)**             | 3                  | 10 sec           | Reports by type (IKE_SA_INIT, IKE_AUTH, CREATE_CHILD_SA), delay diagram, errors                 |
| **GTPv2-C (S2b)**           | 4                  | 10 sec           | Messages (Create/Modify/Delete Session), delays, errors, relays                                 |
| **GTP-U data plane**        | 3                  | 10 sec           | Packets/bytes, tunneling errors                                                                 |
| **Diameter (SWm/SWx/S6b)**  | 5                  | 10 sec           | Command code messages (DER/DEA, MAR/MAA, AAR/AAA), delays, errors, watchdog, connection status  |
| **Service KPI**             | 4                  | 10 sec           | Percentage of successful attempts, duration histogram, service availability, uptime             |
| **Session State**           | 4                  | 10 sec           | IKE SA, Child SA, GTP sessions, all users                                                       |
| **Application**             | 3                  | 10 sec           | Number of streams, memory, log messages by levels                                               |
| **System**                  | 4                  | 10 sec           | CPU recycling, memory, memory disposal, open FD                                                 |
| **Total**                   | **33 metrics**     |                  |                                                                                                 |

===== Naming principles =====

All metrics have the prefix ''epdg_'' and are organized in a hierarchy:

<code>
epdg_
├── config_*           # Configuration
├── network_*          # Network layer
├── ikev2_*            # SWu (IKEv2/IPSec)
├── gtp_*              # S2b control-plane GTPv2-C
├── gtpu_*             # S2b data-plane GTP-U
├── diameter_*         # SWm/SWx/S6b
├── service_*          # Service KPIs (attach, availability, uptime)
├── session_*          # Session Status (IKE SA, Child SA, GTP, subscribers)
├── app_*              # App Metrics (memory, threads, logs)
└── system_*           # System metrics (CPU, disk, network)
</code>