Editing Technical Training Serssions 2021 Linux Team (section)

==Session for Introduction with Technologies - Generic . Dated 24th Mar 2021 ==

{{#ev:youtube|PGeTUt9vj50|640}}

'''Video summary:''' "Training Session 2021 march 1" -- a clear, well-recorded English-language company-wide technology overview and onboarding session (unlike most of the other videos on this page, this one has good transcript quality throughout). A senior team member walks newer staff (Sanju, Chandrakant, and others) through the breadth of technologies Tetra supports across its client base, and points them to Tetra's internal wiki (the same wiki this cleanup project is auditing) as the canonical source of implementation, fine-tuning, release, integration, and deployment-issue documentation -- explicitly framing it as an asset built up by the whole team over years that new hires must be given access to and contribute back into. Covers, in order: Zimbra (open source and enterprise, from small to very large/enterprise deployments); cloud platforms used (AWS, Google Cloud, Linode, DigitalOcean); DRBD clustering as a "poor man's cluster" used when a customer won't provide dedicated SAN/LUN storage (cited customers: RDM, News Nation); full open-source Linux-based data center builds for customers like RDM (firewalls, mail, AD, virtualization all on Linux); backup tooling (Bacula for Capital Bank; Amanda/Zamanda for Infosys DOP's DR/DC services); Postfix as a critical, deeply-understood component underlying Zimbra; PHP/LAMP applications requiring deep Apache/PHP/MySQL tuning at scale, including a hospital-management LAMP application; JBoss + PostgreSQL deployments (Beetel's Java application, built in-house, requiring JBoss/JDK performance tuning); Samba as a Linux-based AD replacement for large customers like GSTN, alongside a note that for very large/sensitive clients Tetra often works L3/L4 alongside an on-site L1/L2 team; Trend Micro IMSS (Internet Messaging Security Suite) for mail security, deployed for a customer called Pahwa; a potted history of Tetra's mail-server technology evolution (sendmail in 1997-98, qmail from 1998 through ~2010-2011, then migration to Zimbra), with qmail still living on inside the Kloxo control panel (a free, open-source cPanel-alternative demoed live, used for small customers needing basic mail/DNS/PHP/MySQL hosting); Tetra's own mail-relay infrastructure (three relay servers, Postfix-based, needed because major cloud platforms block direct outbound mail, requiring correct DKIM/SPF/domain setup); Oracle OVM as a virtualization platform (used by Capital Bank); RHEV and its free/open-source equivalent oVirt as enterprise virtualization platforms (RHEV deployed for GSTN); Red Hat Satellite for patch/system management; and the ELK stack (and its packaged form, Graylog) for centralized log management and dashboarding at scale, with large deployments at Infosys and as part of the GSTN portal's monitoring stack.