ASTRA LEARNING PATH · ADVANCED

Senior Hosting Engineer

Diagnose DNS, email, website and infrastructure failures using evidence.

What you will master

An escalation-focused programme covering systematic triage, service logs, mail and DNS failures, HTTP/PHP/database errors, Nagios monitoring and detailed Virtualizor administration.

32 lectures·20 guided hours·Astra text and voice

Course curriculum

Incident triage and severityStabilise service while collecting reproducible facts.
28 min
Layered troubleshooting methodTest from DNS and network through TLS, HTTP and application dependencies.
32 min
Evidence, timelines and change correlationPreserve timestamps, commands and changes for escalation and review.
28 min
Mitigation, rollback and customer updatesRestore service safely before pursuing every root-cause detail.
26 min

Delegation and authoritative DNS failuresTrace root, TLD, parent delegation and authoritative answers.
34 min
Record errors, TTL and negative cachingFind missing, conflicting or stale DNS data.
32 min
DNSSEC validation incidentsDiagnose broken chains of trust and expired signatures.
34 min
Split DNS, reverse DNS and propagation casesHandle internal/external answers, PTR ownership and migration timing.
34 min

SMTP transaction and delivery pathTrace submission, routing, queueing, remote response and mailbox delivery.
34 min
Mail queues and Exim logsFind a message by sender, recipient and ID without guessing.
38 min
SPF, DKIM, DMARC and alignmentDiagnose authentication failures beyond record presence.
38 min
Reputation, blocks and remote rejectionSeparate local configuration from recipient policy and IP reputation.
32 min

HTTP 403 and 404 errorsSeparate permissions, access rules, routing and missing resources.
32 min
HTTP 500 and PHP failuresTrace syntax, fatal, memory, version and extension errors.
38 min
502, 503 and 504 upstream failuresDiagnose proxy, PHP-FPM, application saturation and timeouts.
38 min
Database, disk, inode and quota incidentsRecognise failures caused by state or resource exhaustion.
38 min

Web, PHP, database and system logsChoose the log closest to the failed layer.
36 min
Process, socket and resource toolsUse ps, top, ss, lsof, free, df, du and iostat safely.
38 min
Packet and HTTP diagnosticsUse curl, openssl, dig, traceroute and tcpdump for targeted proof.
40 min
Root cause analysis and post-incident reviewMove from trigger to contributing conditions and prevention.
30 min

Nagios architecture and object modelUnderstand Core, plugins, hosts, services and state transitions.
32 min
Plugins, agents and remote checksDesign meaningful local and remote measurements.
34 min
Notifications, escalation and dependenciesReduce alert noise while preserving urgent signals.
36 min
Downtime, flapping, trends and capacityOperate maintenance windows and identify unstable services.
32 min

Virtualizor architecture and supported virtualizationMap master, slave, hypervisor and management planes.
34 min
Servers, groups, users, ACLs and plansDesign delegated administration and repeatable VPS products.
38 min
Storage, IP pools, bridges, VLAN and NATDesign storage and network allocation for virtual servers.
42 min
OS templates, ISO images and mediaBuild controlled installation sources and lifecycle them safely.
34 min

Create, edit and manage a VPSOperate CPU, memory, disk, network, boot and power settings.
45 min
Console, rescue, password and reinstallationRecover access without losing data unnecessarily.
38 min
Backups, cloning, migration and high availabilityMove and recover workloads while controlling consistency and downtime.
48 min
Firewall, load balancer, DNS, statistics, logs and APIOperate advanced Virtualizor services and automation one feature at a time.
50 min