New Xrootd Monitoring Stream Federated Data Workshop September

New Xrootd Monitoring Stream Federated Data Workshop September 13, 2012 Andrew Hanushevsky, SLAC http: //xrootd. org

Current Monitoring State xrootd provides a wide range of data Periodic summary data (xml based) n Real time detail data (binary based) n n Login identification n Filename mapping information n File access information n n Seek based I/O File close summary (bytes r/w only) Major efforts ongoing to digest data Atlas: Julia Andreeva, Danila Oleynik, Artem Petrosyan, and Ilija Vukotic n CMS: Matevz Tadel n September 13, 2012 IN 2 P 2 Federated Data Workshop 2

The Monitoring Issue Only detail stream provides sufficient data n Used to derive intermediate information n Real-Time n Though difficult to get it reasonably correct n Sigma’s n per-file transfers for I/O block size Raw data far exceeds derived data size n Desire n to send just enough data Less likely to overwhelm collector Solution is to create a new “f” stream September 13, 2012 IN 2 P 2 Federated Data Workshop 3

The New Real-Time “f” Stream Binary stream for only file-based information n Intermediate detail between summary and detail n Provides accurate Real-Time per-file transfers n Computed Sigma’s for I/O block size n Configured via the xrootd. monitor directive n Option: September 13, 2012 fstats interval [fn] [io] [ops] [sigma] n fn include filename in open record n io provide per-file I/O statistics each interval n ops include operation counts in close record n Sigma calculate sigma values IN 2 P 2 Federated Data Workshop 4

The “f” Stream Open Record Inserted into stream when file opened struct Xrd. Xrootd. Mon. File. Hdr // 8 { char rec. Type; // close | io | open | ops | time char rec. Flag; // Record type-specific flags (e. g. open mode, fn present, etc) short rec. Size; // Size of this record in bytes int file. ID; // dictid of file for all rectypes except "time“ }; struct Xrd. Xrootd. Mon. File. Opn { Xrd. Xrootd. Mon. File. Hdr; long fsz; // tfn[]; }; September 13, 2012 // // // 8 8 file size at time of open n "<tid>n<lfn>" of size(Hdr. Rec. Size - 16) IN 2 P 2 Federated Data Workshop 5

The “f” Stream I/O Record One record per open file (each interval) struct Xrd. Xrootd. Mon. Stat. IO { long read; long readv; long write; }; struct Xrd. Xrootd. Mon. File. IO { Xrd. Xrootd. Mon. File. Hdr; Xrd. Xrootd. Mon. Stat. IO Bytes; }; September 13, 2012 // Bytes read from file so far using read() // Bytes read from file so far using readv() // Bytes written to file so far // 8 // 24 IN 2 P 2 Federated Data Workshop 6

The “f” Stream close Record I One record per open file (each interval) n Operation count information (only if ops or sigma selected) struct Xrd. Xrootd. Mon. Stat. Ops { int read; int readv; int write; short rs. Min; short rs. Max; long rsegs; int rd. Min; int rd. Max; int rv. Min; int rv. Max; int wr. Min; int wr. Max; }; September 13, 2012 // // // Number of Smallest Largest read() readv() write() readv() read() readv() write() IN 2 P 2 Federated Data Workshop calls segment count segments request size segment size request size 7

The “f” Stream close Record II One record per closed file n Operation sigma information (only if sigma selected) struct Xrd. Xrootd. Mon. Stat. SD { int read; // Sigma int readv; // Sigma Int rsegs; // Sigma int write; // Sigma wr. Max; // Largest write() request }; struct Xrd. Xrootd. Mon. File. Ops { Xrd. Xrootd. Mon. File. Hdr; Xrd. Xrootd. Mon. Stat. Ops; Xrd. Xrootd. Mon. Stat. SD Sigma; }; September 13, 2012 for readv for seg for write size size // 8 // 48 // 16 IN 2 P 2 Federated Data Workshop 8