@@ -98,7 +98,7 @@ In addition, in the framework of the computing R\&D activities in Italy, the des
\section{Role and contribution of the INFN Tier1 at CNAF}
CNAF is a full-fledged ALICE Tier1 centre, having been one of the first to join the production infrastructure years ago. According to the ALICE cloud-like computing model, it has no special assigned task or reference community, but provides computing and storage resources to the whole collaboration, along with offering valuable support staff for the experiment’s computing activities. It provides reliable xrootd access both to its disk storage and to the tape infrastructure, through a TSM plugin that was developed by CNAF staff specifically for ALICE use.\\
As a result of flooding, the CNAF computing centre stopped operation on November 8th, 2017; tape access had been made available again on January 31st 2018, and the ALICE Storage Element was fully recovered by February 23th. The loss of CPU resources during the Tier1 shutdown was partially mitigated by the reallocation of the Tier1 worker nodes located in Bari to the Tier2 Bari queue. At the end of February 2018 the CNAF local farm had been powered again moving from 50 kHS06 gradually to 140 kHS06. In addition, on March 15th 170 kHS06 at CINECA became available thanks to a 500 Gb/s dedicated link.
As a result of flooding, the CNAF computing centre stopped operation on November 9th, 2017; tape access had been made available again on January 31st 2018, and the ALICE Storage Element was fully recovered by February 23th. The loss of CPU resources during the Tier1 shutdown was partially mitigated by the reallocation of the Tier1 worker nodes located in Bari to the Tier2 Bari queue. At the end of February 2018 the CNAF local farm had been powered again moving from 50 kHS06 gradually to 140 kHS06. In addition, on March 15th 170 kHS06 at CINECA became available thanks to a 500 Gb/s dedicated link.
Since March running at CNAF has been remarkably stable: for example, both the disk and tape storage availabilities have been better than 98\%, ranking CNAF in the top 5 most reliable sites for ALICE. The computing resources provided for ALICE at the CNAF Tier1 centre were fully used along the year, matching and often exceeding the pledged amounts due to access to resources unused by other collaborations. Overall, about 64\% of the ALICE computing activity was Monte Carlo simulation, 14\% raw data processing (which takes place at the Tier0 and Tier1 centres only) and 22\% analysis activities: Fig.~\ref{fig:runjobsusers} illustrates the share among the different activities in the ALICE running job profile along the last 12 months.\\
\begin{figure}[!ht]
\begin{center}
...
...
@@ -126,7 +126,7 @@ Since mid-November a new job submission queue has been made available to ALICE a
\caption{Running jobs profile at CNAF in 2018.}
\label{fig:rjobsCNAFunov}
\end{figure}
At the end of the last year ALICE was keeping on disk at CNAF more than 4.1 PiB of data in nearly 118 million files, plus more than 10 PiB of raw data on custodial tape storage; the reliability of the storage infrastructure is commendable, even taking into account the extra layer of complexity introduced by the xrootd interfaces. The excellent FS performances allow to analyse data from SE with an average throughput of about 1.6 GB/s and a peak throughput of about 3.0 GB/s, as shown in Fig.\ref{fig:nettrafse}.
At the end of the last year ALICE was keeping on disk at CNAF more than 4.1 PiB of data in nearly 118 million files, plus more than 10 PiB of raw data on custodial tape storage; the reliability of the storage infrastructure is commendable, even taking into account the extra layer of complexity introduced by the xrootd interfaces. The excellent filesystem performances allow to analyse data from the storage elements with an average throughput of about 1.6 GB/s and a peak throughput of about 3.0 GB/s, as shown in Fig.\ref{fig:nettrafse}.
