# Presentation: 658680

## Globus Monitoring and Discovery Service (MDS)

- Jennifer Schopf
- Argonne National Laboratory
- June 14, 2002

## MDS: Monitoring and Discovery Service

- Globus Information Service
- Used by iVDGL, GriPhyN, PPDG, EDG, NMI, Grads, NorduGrid, etc.
- Requirements and characteristics
- Uniform, flexible access to information
- Scalable, efficient access to dynamic data
- Access to multiple information sources
- Decentralized maintenance
- Secure information provision
- Main contact John McGee (mcgee@isi.edu)

- Globus Monitoring and Discovery Service, Jennifer Schopf

- June 14, 2002

## MDS Architecture

- Resources run a standard information service (GRIS) that speaks LDAP and provides information about the resource
- GIIS provides a “caching” service
- Resources register with GIIS
- GIIS pulls information when requested by a client (when out of date)
- GIIS provides the collective-level indexing/searching function

**GIIS**
- Cache contains info from A and B

- GRIS register with GIIS
- GIIS requests info
- from GRIS services

- Client 1

- Client 2

- Client 1 requests  infodirectly from resources.

- Client 2 uses GIIS for searching
- collective information.

- Globus Monitoring and Discovery Service, Jennifer Schopf

- June 14, 2002

**Notes:**
GIIS is an index node. Index nodes can be designed and optimized for various requirements

## Protocols

- MDS protocols based on LDAP
- Dynamic Registration via Reg. Protocol (GRRP)
- soft-state protocol
- Resource Inquiry via Info. Protocol (GRIP)
- Co-located with resource on network
- Resource Discovery (via GRIP or other)
- Using GRIP allows resource/directory hierarchy
- Also well defined interfaces to add new sensor data

- Globus Monitoring and Discovery Service, Jennifer Schopf

- June 14, 2002

## Soft-state Registration

- Periodic notification
- “Service/resource is available”
- Expected-frequency metadata
- Automatic directory construction
- Add new resources to directory
- Invite resources to join new directory
- Self-cleaning
- Reduce occurrence of “dead” references

- Globus Monitoring and Discovery Service, Jennifer Schopf

- June 14, 2002

## MDS-2 Implementation

- Grid Information Service (GRIS)
- Provides resource description
- Modular content gateway
- Grid Index Information Service (GIIS)
- Provides aggregate directory
- Hierarchical groups of resources
- NOTE: EDG Ftree
- flexible backend for MDS by EDG WP3
- currently in EDG testbed installation of MDS

- Globus Monitoring and Discovery Service, Jennifer Schopf

- June 14, 2002

## MDS-2.1 GRIS Providers

- grid-info-cpu reports CPU/load info
- grid-info-fs reports filesystem info
- grid-info-mem reports RAM/VM info
- grid-info-net reports NIC/net info
- grid-info-os reports OS info
- grid-info-platform reports arch. info
- grid-info-merged merges all host info*
- Extensible for other sources, e.g. GRAM

- Globus Monitoring and Discovery Service, Jennifer Schopf

- June 14, 2002

## What’s next for MDS (core)

- MDS 2.2 expected in July 2002
- Will harden the 2.1 code
- Additional performance improvements
- Address some of the packaging difficulties that occurred with 2.1
- Updated schemas (GLUE-schema project)
- Notification is currently not included in MDS 2.2 because it was not required as part of the use cases gathered by the joint monitoring group
- The following release will likely be the OGSA-ified version, currently under discussion, and will include notification

- Globus Monitoring and Discovery Service, Jennifer Schopf

- June 14, 2002

## 2.1 GRIS Provider Times

| OS | RH 6.2 | RH7.1 | Irix | Solaris |
| --- | --- | --- | --- | --- |
| Platform | 0.04 | 0.03 |  |  |
| Os | 0.06 | 0.04 |  |  |
| Cpu | 0.28 | 0.15 |  |  |
| Mem | 0.12 | 0.10 |  |  |
| Fs | 0.14 | 0.09 |  |  |
| Net | 0.45 | 0.17 |  |  |
| Merge | 0.80 | 0.37 |  |  |
| total | 1.89 | 0.95 |  |  |
| OLD | 10.01 | N/A | 8.29 | 18.27 |

- Globus Monitoring and Discovery Service, Jennifer Schopf

- June 14, 2002

## GRIS Response Issues

- MDS 2.0 and 2.1 are lazy
- Probes are not issued unless queried
- Some system probes are slow
- “Best” probe may take several seconds
- How to avoid stale data?
- Clients set time-out per query
- GRIS/GIIS define time-out per source
- Fresh data found before timeout is returned
- Cache fill continues after client time-out

- Globus Monitoring and Discovery Service, Jennifer Schopf

- June 14, 2002

## What next for MDS Monitoring

- Leading the effort to have common schemas between EDG and US projects
- Defining additional information providers in cooperation with sensor developers
- Eg. Using Ganglia for cluster-level monitoring

- Globus Monitoring and Discovery Service, Jennifer Schopf

- June 14, 2002

## GridFTP Monitoring

- We added basic logging to GridFTP
- source address, file name, file size, number of parallel streams, TCP buffer size, start and end timestamps, total time consumed, aggregate bandwidth achieved, read/write
- There’s also an information provider available
- www-unix.mcs.anl.gov/~vazhkuda/GridFTP-Information-Provider/
- And a paper talking about predictions
- www.globus.org/research/papers/Prediction-Paper-249.pdf

- Globus Monitoring and Discovery Service, Jennifer Schopf

- June 14, 2002

## Things to think about when comparing systems

- What is the main use case your system addresses?
- Resource selection
- What are the base set of sensors given with a system?
- (see several slides ago)
- How does that set get extended?
- Well defined process for wriring an information provider to act as a front end to any sensor and translate the data into ldap – see www.globus.org/mds/creating_new_providers.pdf
- What are you doing for discovery/registry?
- We use an embeded discovery/registry

- Globus Monitoring and Discovery Service, Jennifer Schopf

- June 14, 2002

## Comparing 2

- What schema are you using (do you interact with)?
- Globus defined it’s own schema for MDS 2.1 release, will be using GLUE-schema as well in MDS 2.2
- Is this system meant to monitor a machine, a cluster, or send data between sites, or some combination of the above?
- This system interfaces to machine, cluster or site data, and communicates that information between sites. It is not meant to replace a site monitoring system. It is meant to be used to have a common infrastructure to allow interoperablity between site monitoring systems

- Globus Monitoring and Discovery Service, Jennifer Schopf

- June 14, 2002

## Comparing 3

- What kind of testing has been done in terms of scalability
- This is in progress- but the software is currently being used by iVDGL, GriPhyN, PPDG, EDG, NMI, NPACI, NCSA, Grads, NorduGrid, etc.

- Globus Monitoring and Discovery Service, Jennifer Schopf

- June 14, 2002

## Glue Schema Status

- Jennifer Schopf
- Argonne National Lab
- May 23,2002

## GLUE-Schema Effort

- Part of HICB/JTB GLUE framework
- To address need to common schemas between projects
- framework independent
- something to translate into, not a requirement within fabric layer
- maillist: glue-schema@hicb.org
- www.hicb.org/glue/glue-schema/schema.html

- Globus Monitoring and Discovery Service, Jennifer Schopf

- June 14, 2002

## Problems with Schema’s

- Naming MetaData implies a structure, e.g. relational, hierarchical, etc
- Attribute/Measurement units
- Attribute/Measurement naming
- Object/Entity naming
- Representation of a schema (LDAP, SQL, XML, CIM, etc)
- A lot of schemas out there
- information, monitoring, scheduling, accounting, security, and more!

- Globus Monitoring and Discovery Service, Jennifer Schopf

- June 14, 2002

## Goal

- Define a minimum common schema requirement for interoperability
- Compute Elements, Network Elements, Storage Elements
- EDG, DataTag, PPDG, GriPhyN, iVDGL, etc.!
- First step of this achieved
- CE schema currently being implemented by both Globus and EDG information providers
- SE schema currently under discussion on mailing list

- Globus Monitoring and Discovery Service, Jennifer Schopf

- June 14, 2002

## Spreadsheet version 12

- Listing EDG, Globus and new schemas for CE
- First draft March 19
- 12+ calls, more than 500 emails,  and MANY hours of work later... here we are!
- Draft 12 sent out May 22 pm

- Globus Monitoring and Discovery Service, Jennifer Schopf

- June 14, 2002

## Document v. 6

- Layered structure: CE, cluster, (homogeneous) subcluster, node
- Attributes collected into object classes
- UML class diagram for generic representation
- Currently being mapped into ldap/sql/xml

- Globus Monitoring and Discovery Service, Jennifer Schopf

- June 14, 2002

## GLUE-Schema Structure

- Globus Monitoring and Discovery Service, Jennifer Schopf

- June 14, 2002

## Status

- Implementation of information providers beginning
- MDS information providers with new schemas part of the MDS 2.2 release, mid July
- EDG information providers need updating as well
- Test between EU and US planned for July

- Globus Monitoring and Discovery Service, Jennifer Schopf

- June 14, 2002

## After CE we have SE and NE

- Discussion of SE’s has started
- Experts have been asked to join in
- Arie Shoshani, John Gordon
- Glue Storage Model beginning to be discussed to understand general constraints
- NE will be addressed after this

- Globus Monitoring and Discovery Service, Jennifer Schopf

- June 14, 2002

## Additional Information

- MDS information
- www.globus.org/mds/
- GLUE-schema
- www.hicb.org/glue/glue-schema/schema.html

- Globus Monitoring and Discovery Service, Jennifer Schopf

- June 14, 2002