* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Gancho_ADC_weekly_24thJan2012
Survey
Document related concepts
Global serializability wikipedia , lookup
Commitment ordering wikipedia , lookup
Microsoft Access wikipedia , lookup
Microsoft SQL Server wikipedia , lookup
Serializability wikipedia , lookup
Entity–attribute–value model wikipedia , lookup
Open Database Connectivity wikipedia , lookup
Extensible Storage Engine wikipedia , lookup
Functional Database Model wikipedia , lookup
Ingres (database) wikipedia , lookup
Oracle Database wikipedia , lookup
Concurrency control wikipedia , lookup
Microsoft Jet Database Engine wikipedia , lookup
Relational model wikipedia , lookup
Versant Object Database wikipedia , lookup
Clusterpoint wikipedia , lookup
Transcript
ADC weekly, 24th January 2012 Status of the ATLR and ADCR after the database upgrade and hardware migration on 17th Jan 2012 Gancho Dimitrov 24-Jan-2012 Gancho Dimitrov 1 ATLR and ADCR Successful and within the foreseen downtime interventions on the ATLR and ADCR databases (17th January 2012 10:00-14:00). Thanks to all people involved and in particular to the the PhyDB DBAs. ADCR is with increased number of nodes in the database cluster: from 3 before to 4 nodes now. No issues with connectivity. All applications were able to connect without problems to the new database. Visible decrease in the load on the database machines. In particular on the ADCR1 (DQ2) and ADCR2 (PanDA) instances (not much user workload on the ATLR yet). The new HW with 3 times larger data pool cache and storage with SSD cache brought down the IO requests and thus the CPU usage as well. 24-Jan-2012 Gancho Dimitrov 2 ADCR1 database instance (DQ2) 24-Jan-2012 Gancho Dimitrov 3 ADCR2 database instance (PanDA) 24-Jan-2012 Gancho Dimitrov 4 ADCR3 database instance (LFC) 24-Jan-2012 Gancho Dimitrov 5 Issues found 1) Row lock contention from update activity on the PANDAMETA.CACHE table. => Initially under suspition was a contention on the LOB (Large Object) segments of the table. However the encoded implementation on the client side needs to be verified. The issue currently under investigarion with trials on reproducing the problem on a the INT8R testbed. 2) Partial replication of the ATLAS_MDT_DCS schema. => Turned to be due to silent supress of the tables which have partitions with compressed data. Implemented workaround last Friday (20th Jan) and since then the replication for this account is in synch. 3) Increased rate of disk reads on the ADCR2 instance (PanDA) Under investigation now... Few queries on focus with high execution rate or changed execution plan or changed time range of interest (for example, the ‘wnList’ query of PanDA monitor) 24-Jan-2012 Gancho Dimitrov 6 ADCR2 (PanDA) megabytes read per sec 24-Jan-2012 Gancho Dimitrov 7 ADCR1 (DQ2) megabytes read per sec 24-Jan-2012 Gancho Dimitrov 8 Conclusions (+ a reminder) Successful DB interventions with a minimal possible database downtime. All that due to the efforts of many people. Special thanks to the PhyDB support. Ongoing work on evaluating the user workload and the Oracle 11g behaviour. And a reminder for the need of a short downtime of the databases for change of the Oracle ‘compatible’ parameter. Below is extract from Dario’s presentation ADC weekly, 20th Dec 2011. 24-Jan-2012 Gancho Dimitrov 9