System Management: Node Configuration & Software Package Management

1. System Management:Node Configuration &Software Package Management German.Cancio@cern.ch

2. System management Architecture • The pillars: • Central Configuration Database • Node Configuration Management • Base system installation • Software Package Management • Monitoring

3. Node Configuration Management

4. GUI Node Configuration Management Client Server Component Access API High Level API HLDL Low Level API PAN DBM XML Notification + Transfer

5. Node Configuration Management (NCM) • Client software running on the node which takes care of “implementing” what is in the configuration profile • Sits on top of the low-level Config access library (NVA-API) • Modules: • “Components” • Component support libraries • Framework

6. NCM: Components • “Components” (like SUE “features” or LCFG ‘objects’) are responsible for updating local config files, and notifying services if needed • Components register their interest in configuration entries or subtrees, and get invoked in case of changes • Components do only configure the system • Usually, this implies regenerating and/or updating local config files (eg. /etc/sshd_config) • Use standard system facilities (SysV scripts) for managing services • Reuse the standard facilities: most services come with a SysV script. • Components can notify services using SysV scripts when their configuration changes. • Components are kept small&simple

7. Component example sub Configure { my ($self) = @_; # access configuration information my $config=NVA::Config->new(); my $arch=$config->getValue('/system/architecture’); # low-level API $self->Fail (“not supported") unless ($arch eq ‘i386’); # (re)generate and/or update local config file(s) open (myconfig,’/etc/myconfig’); … # notify affected (SysV) services if required if ($changed) { system(‘/sbin/service myservice reload’); … } }

8. Existing component taxonomy • Components can be classified into basic, service-specific and Gridcomponents • Basic components: Manage basic system configurations • eg. network,NFS, printers, security, time… • Service specific components: For batch nodes, servers (provided by service managers) • Eg. LSF, PBS, Castor, accounting, root mail, … • Grid components (provided by Grid middleware WP’s) • Eg. Globus, GDMP, LCAS, Resource Broker… • Existing components are available both from SUE and LCFG • SUE features: Basic and Service specific • LCFG components: Basic and Grid components • Need complete classification (which components to port, which ones to rewrite) • Functionality -> component

9. NCM: Component support libraries Component support libraries for recurring tasks: • Logging and error reporting • Template processor (for fast config file generation) • SUE sysmgt libraries • Eg. check/edit files, system information, regexps, crontab, (x)inetd… • Monitoring integration

10. NCM: framework A light weight framework (cdisp) glues the components to the Configuration Client. Overall functionality: • Register which components are interested in which configuration entries/subtrees • Upon a config update, look up the components which need to be invoked • Ordering of component invocations according to dependencies • Invocation of components

11. XML server client cdisp Components Components Components Node Config Client Node Config Mgmt Component libs SUE sysmgt Logging Template processor Monitoring interface NCM Architecture DBM Cache registration & notification “Low-level” API NVA API “High-level” API CCConfig Invocation Configure()

12. Software Package Management

13. Software Distribution Architecture •  A packaging tool takes care of installing/deinstalling/upgrading packages on a computer node and keeps an inventory of currently installed packages. •  The packages themselves are stored on a managed Software Repository accessible via multiple protocols (eg. HTTP, FTP, shared file system,..) •  Information on which packages are to be deployed on which nodes, and which packages are available on which repositories, is kept in the fabric-wide Configuration Database. •  A 'glue' application (running on the target nodes) computes the necessary package upgrade operations and invokes the packaging tool. • (The SW generation and packaging process is outside the scope.)

14. Software Package Manager (SPM) • The SPM is the glue application. Functionality: • Compares the packages currently installed on the local node with the packages listed in the configuration • Computes the necessary install/deinstall/upgrade operations • Invokes the packager with the right operation transaction set • The SPM is driven via a local configuration file • For batch/servers: A component generates/maintains this cf file out of CDB information • For desktops: Possible to write a GUI for locally editing the cf file • The SPM core is independent of which packaging format is used.

15. Software Package Manager (II) • Packager: the standard system packaging format is used (rpm for Linux, pkg for Solaris) • rpmt (for rpm ‘transactional’) used for transactions handling • Packager (rpmt) functionality: • Read operations (transaction) • downloads new packages from Repository • orders the transaction operations taking into account dependency information • Executes the operations (installs/removes/upgrades)

16. Central Config DB Component rpmt SPM external SPM Repository packages Package files filesystem SPM Architecture Desktops GUI “desired” configuration Local Config file Packages (RPM, pkg) Installed pkgs Transaction set HTTP(S), NFS, FTP RPM db

17. Manpower

18. Manpower requirements NCM SPM • Grand total: 32 PW (=7.4 PM) for LCG1, 58 PW (13.5 PM) for full solution • Required manpower type: System+perl programming/development expert  • Available WP4-install development manpower (from R2.0 on): 0.3 (Enrico) + 0.15 (German) • Edinburgh?