Creating Complex Network Services with eBPF: Experience and Lessons Learned

The extended Berkeley Packet Filter (eBPF) is a recent technology available in the Linux kernel that enables flexible data processing. However, so far the eBPF was mainly used for monitoring tasks such as memory, CPU, page faults, traffic, and more, with a few examples of traditional network services, e.g., that modify the data in transit. In fact, the creation of complex network functions that go beyond simple proof-of-concept data plane applications has proven to be challenging due to the several limitations of this technology, but at the same time very promising due to some characteristics (e.g., dynamic recompilation of the source code) that are not available elsewhere. Based on our experience, this paper presents the most promising characteristics of this technology and the main encountered limitations, and we envision some solutions that can mitigate the latter. We also summarize the most important lessons learned while exploiting eBPF to create complex network functions and, finally, we provide a quantitative characterization of the most significant aspects of this technology

Toward an eBPF-based clone of iptables

Iptables, which is currently the most common firewall on Linux, has shown several limitations over the years, with scalability as a big concern. This paper reports the first results of a project that aims at creating a (partial) clone of iptables, using the eBPF/XDP technology. This project assumes unmodified Linux kernel and guarantees the full compatibility (in terms of semantics and syntax) with current iptables

VALUTAZIONE DEL DANNO PRIMARIO ED OSSIDATIVO AL DNA IN LINFOCITI SALIVARI PER IL MONITORAGGIO DEGLI EFFETTI BIOLOGICI PRECOCI CAUSATI DALL’INQUINAMENTO ATMOSFERICO NEI BAMBINI: STUDIO MAPEC

VALUTAZIONE DEL DANNO PRIMARIO ED OSSIDATIVO AL DNA IN LINFOCITI SALIVARI PER IL MONITORAGGIO DEGLI EFFETTI BIOLOGICI PRECOCI CAUSATI DALL’INQUINAMENTO ATMOSFERICO NEI BAMBINI: STUDIO MAPEC Samuele Vannini (1) - Sara Levorato (1) - Elisabetta Ceretti (2) - Milena Villarini (1) - Silvia Bonetta (3) - Cristina Fatigoni(1) - Annalaura Carducci (4) - Tania Salvatori (1) - Maria Rosaria Tumolo (5) - Alessio Perotti (6) - Silvia Bonizzoni (7) - Alberto Bonetti (8) - Massimo Moretti (1) - Umberto Gelatti (2) Dipartimento di Scienze Farmaceutiche, Università degli Studi di Perugia, Perugia, Italia (1) - Dipartimento di Specialità Medico-Chirurgiche, Scienze Radiologiche e Sanità Pubblica, Università degli Studi di Brescia, Brescia, Italia (2) - Dipartimento di Scienze della Sanità Pubblica e Pediatriche, Università degli Studi di Torino, Torino, Italia (3) - Dipartimento di Biologia, Università degli Studi di Pisa, Pisa, Italia (4) - Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali, Università del Salento, Lecce, Italia (5) - Dipartimento di Bioscienze, Università del Studi di Parma, Parma, Italia (6) - Ufficio Minori, Comune di Brescia, Brescia, Italia (7) - Centro Servizi Multisettoriale e Tecnologico, Csmt Gestione S.c.a.r.l., Brescia, Italia (8) Il particolato è l’inquinante atmosferico che provoca i maggiori danni alla salute umana in Europa (Agenzia Europea dell’Ambiente; www.eea.europa.eu). Tra le prime 30 città più inquinate del continente, oltre la metà sono italiane, in particolare quelle situate nella pianura Padana, con concentrazioni di PM10, PM2,5 e NOx ben al di sopra dei valori di riferimento europei. Studi epidemiologici hanno rilevato un’associazione positiva tra esposizione ad inquinamento atmosferico, soprattutto al PM, ed incidenza e mortalità per diverse malattie cronico-degenerative, come cancro al polmone, malattie cardiovascolari e diabete. I bambini, in particolar modo, risultano esposti ad un elevato rischio per quanto riguarda gli effetti a breve e lungo termine dell’inquinamento atmosferico. Dati recenti suggeriscono che alcune alterazioni genetiche che si verificano nella prima infanzia posso incrementare il rischio di malattie cronico-degenerative in età adulta. L’obiettivo dello studio MAPEC (Monitoring Air Pollution Effects on Children for supporting Public Health policy) è quello di valutare l’associazione tra inquinamento atmosferico e biomarcatori di effetti genotossici precoci nei bambini, e di proporre un modello per la stima del rischio globale causato dagli inquinanti atmosferici. Lo studio ha previsto il reclutamento di circa 1.000 bambini, di età compresa tra 6-8 anni, in cinque città italiane (200 bambini per città) caratterizzate da diverse concentrazioni di inquinanti atmosferici: Brescia, Torino, Pisa, Perugia e Lecce. Campioni di saliva sono stati raccolti in due differenti stagioni, inverno e primavera, caratterizzate da differenze qualitative e quantitative degli inquinanti atmosferici (1.000 × 2 = 2.000 campioni). Nei linfociti salivari è stato valutato il danno primario e ossidativo al DNA mediante il test della microgel elettroforesi su singole cellule (comet assay). Alla conferenza verranno presentati i risultati preliminari relativi al campionamento invernale

Thymidylate synthetase mRNA levels are increased in liver metastases of colorectal cancer patients resistant to fluoropyrimidine-based chemotherapy

BACKGROUND: Fluoropyrimidines such as 5-fluorouracil (5-FU) and 5-fluoro-2'deoxyuridine (FUDR) are among the most effective chemotherapeutic agents for treatment of metastatic colorectal cancer (CRC). Increased expression of thymidylate synthetase (TS) in CRC metastases has been proposed to be an important mechanism of resistance to fluoropyrimidine-based chemotherapy. METHODS: The present study investigated whether TS mRNA levels in liver metastases of 20 CRC patients before treatment with FUDR by hepatic arterial infusion (HAI) correlated with frequency of clinical response or survival duration. RESULTS: Median survival duration of patients with TS mRNA levels above and below the median was 15 and 18 months, respectively (p > 0.05). Clinical response was achieved in 40% of patients with low TS mRNA levels, but in only 20% of patients with high TS mRNA levels (p = 0.01). TS mRNA levels were also measured for liver metastases of 7 of the patients that did not achieve a clinical response. A statistically significant increase in expression of TS mRNA was observed for liver metastases resistant to chemotherapy (21 ± 14) in comparison to liver metastases of the same patients before chemotherapy (8 ± 4) (p = 0.03). CONCLUSION: This is the first report to demonstrate increased TS expression in liver metastases from CRC patients resistant to fluoropyrimidine based chemotherapy. These findings are consistent with previous studies indicating that increased TS expression is associated with resistance to fluoropyrimidine-based chemotherapy

Colorectal Cancer Stage at Diagnosis Before vs During the COVID-19 Pandemic in Italy

IMPORTANCE Delays in screening programs and the reluctance of patients to seek medical attention because of the outbreak of SARS-CoV-2 could be associated with the risk of more advanced colorectal cancers at diagnosis. OBJECTIVE To evaluate whether the SARS-CoV-2 pandemic was associated with more advanced oncologic stage and change in clinical presentation for patients with colorectal cancer. DESIGN, SETTING, AND PARTICIPANTS This retrospective, multicenter cohort study included all 17 938 adult patients who underwent surgery for colorectal cancer from March 1, 2020, to December 31, 2021 (pandemic period), and from January 1, 2018, to February 29, 2020 (prepandemic period), in 81 participating centers in Italy, including tertiary centers and community hospitals. Follow-up was 30 days from surgery. EXPOSURES Any type of surgical procedure for colorectal cancer, including explorative surgery, palliative procedures, and atypical or segmental resections. MAIN OUTCOMES AND MEASURES The primary outcome was advanced stage of colorectal cancer at diagnosis. Secondary outcomes were distant metastasis, T4 stage, aggressive biology (defined as cancer with at least 1 of the following characteristics: signet ring cells, mucinous tumor, budding, lymphovascular invasion, perineural invasion, and lymphangitis), stenotic lesion, emergency surgery, and palliative surgery. The independent association between the pandemic period and the outcomes was assessed using multivariate random-effects logistic regression, with hospital as the cluster variable. RESULTS A total of 17 938 patients (10 007 men [55.8%]; mean [SD] age, 70.6 [12.2] years) underwent surgery for colorectal cancer: 7796 (43.5%) during the pandemic period and 10 142 (56.5%) during the prepandemic period. Logistic regression indicated that the pandemic period was significantly associated with an increased rate of advanced-stage colorectal cancer (odds ratio [OR], 1.07; 95%CI, 1.01-1.13; P = .03), aggressive biology (OR, 1.32; 95%CI, 1.15-1.53; P < .001), and stenotic lesions (OR, 1.15; 95%CI, 1.01-1.31; P = .03). CONCLUSIONS AND RELEVANCE This cohort study suggests a significant association between the SARS-CoV-2 pandemic and the risk of a more advanced oncologic stage at diagnosis among patients undergoing surgery for colorectal cancer and might indicate a potential reduction of survival for these patients

Enhancements to declarative analysis in ROOT

ROOT is a tool used by virtually every High Energy Physics analysis inside and outside CERN, thanks to the range of functionalities offered. RDataFrame is a ROOT component that offers the user an intuitive functional programming interface and gives access to automatic analysis parallelization. The goal of RDataFrame is to make data analysis as efficient, expressive and simple as possible. This report presents the features added on the RDataFrame during the Summer Student Internship to offer an even more powerful tool to the users

Accelerating Linux Security with eBPF iptables

The sheer increase in network speed and the massive deployment of containerized applications in a Linux server has led to the consciousness that iptables, the current de-facto firewall in Linux, may not be able to cope with the current requirements particularly in terms of scalability in the number of rules. This paper presents an eBPF-based firewall, bpf-iptables, which emulates the iptables filtering semantic while guaranteeing higher throughput. We compare our implementation against the current version of iptables and other Linux firewalls, showing how it achieves a notable boost in terms of performance particularly when a high number of rules is involved. This result is achieved without requiring custom kernels or additional software frameworks (e.g., DPDK) that could not be allowed in some scenarios such as public data-centers

Toward an eBPF-based clone of iptables

Iptables, which is currently the most common firewall on Linux, has shown several limitations over the years, with scalability as a big concern. This paper reports the first results of a project that aims at creating a (partial) clone of iptables, using the eBPF/XDP technology. This project assumes unmodified Linux kernel and guarantees the full compatibility (in terms of semantics and syntax) with current iptables

Is an antiemetic prophylactic treatment needed for patients submitted to consecutive days of 5-fluorouracil? An observational study

Aims and Background. The necessity of an antiemetic prophylaxis in patients treated with chemotherapy of low emetogenic potential, such as 5-fluorouracil +/- folinic acid fractionated over several consecutive days, is controversial. The aim of the study was to evaluate the therapeutic behavior of oncologists on this issue. Methods. All consecutive in and out patients who started chemotherapy in 33 Italian oncological departments from June 24 to July 6, 1996, were studied. The antiemetic prescription pattern and its effectiveness, in patients submitted to 5-fluorouracil +/- folinic acid were evaluated. Results. Of the 1956 patients submitted to cancer chemotherapy, 259 patients received 5-fluorouracil +/- folinic acid. Of these, 186 patients were treated for 5 consecutive days, 47 for 4 days, 20 for 3 days and 6 for 2 days. A total of 219 (84.5%) received an antiemetic prophylaxis: 43.4% a 5-HT3 antagonist +/- steroids, 37.5% an antidopaminergic drug, 10.9% a steroid +/- antidopaminergic drug, and 8.2% other drugs. Only 40 patients (15.5%) did not receive an antiemetic prophylaxis. Overall complete protection from vomiting/nausea was 225/259 (86.9%)/163/259 (62.9%). The complete protection from vomiting/nausea during the 5 days in the 186 patients was not significantly different among patients receiving or not an antiemetic prophylaxis (88.1%/64.9% vs 88.9%/55.6%). At unifactorial analysis, the previous experience of vomiting/nausea caused by chemotherapy was found to be a significant prognostic factor. In fact, overall complete protection from vomiting/nausea was significantly inferior in patients who had previous experience of vomiting/nausea (65.1%/35.0%) with respect to those who did not (91.2%/75.4%, P 0.001, respectively). Conclusions. The study showed that in clinical practice patients submitted to 5-fluorouracil +/- folinic acid obtained a similar high protection from vomiting and nausea regardless of whether or not antiemetic prophylaxis was given. It would be therefore reasonable not to treat patients undergoing such chemotherapy, whereas patients with previous experience of vomiting/nausea caused by chemotherapy should be given an antiemetic prophylaxis