Methods and systems for log management include pre-processing heterogeneous logs and performing a log management action on the pre-processed plurality of heterogeneous logs. Pre-processing the logs includes performing a fixed tokenization of the heterogeneous logs based on a predefined set of symbols, performing a flexible tokenization of the heterogeneous logs based on a user-defined set of rules, converting timestamps in the heterogeneous logs to a single target timestamp format, and performing structural log tokenization of the heterogeneous logs based on user-defined structural information.

Administrators of most user-facing systems depend on periodic log data to get an idea of the health and status of production applications. Logs report information, which is crucial to diagnose the root cause of complex problems. In this paper, we present a real-time log analysis system called LogLens that automates the process of anomaly detection from logs with no (or minimal) target system knowledge and user specification. In LogLens, we employ unsupervised machine learning based techniques to discover patterns in application logs, and then leverage these patterns along with the real-time log parsing for designing advanced log analytics applications. Compared to the existing systems which are primarily limited to log indexing and search capabilities, LogLens presents an extensible system for supporting both stateless and stateful log analysis applications. Currently, LogLens is running at the core of a commercial log analysis solution handling millions of logs generated from the large-scale industrial environments and reported up to 12096x man-hours reduction in troubleshooting operational problems compared to the manual approach.

Es werden Systeme und Verfahren zum Handhaben von Protokolldaten von einer oder mehreren Anwendungen bzw. einem oder mehreren Sensoren oder Instrumenten durch Empfangen von heterogenen Protokollen von beliebigen/unbekannten Systemen oder Anwendungen; Erzeugen von regelmasigen Ausdrucksmustern aus den heterogenen Protokollquellen unter Verwendung von maschinellem Lernen und Extrahieren eines Protokollmusters daraus; Erzeugen von Modellen und Profilen aus Trainingsprotokollen auf der Grundlage verschiedener Bedingungen und Aktualisieren einer globalen Modelldatenbank, in der alle Modelle gespeichert sind, die im Lauf der Zeit erzeugt werden; Tokenisieren von unbearbeiteten Protokollnachrichten von einer oder mehreren Anwendungen bzw. einem oder mehreren Sensoren oder Instrumenten, mit denen ein Produktionssystem lauft; Umsetzen von eingehenden, tokenisierten Stromen in Datenobjekte zur Abweichungsdetektion und Weiterleiten von Protokollnachrichten an diverse Abweichungsdetektoren; und Erzeugen eines Abweichungsalarms von der einen oder den mehreren Anwendungen bzw. dem einen oder den mehreren Sensoren oder Instrumenten, mit denen ein Produktionssystem lauft, offenbart.

Node ranking in temporal networks are often impacted by heterogeneous context from node content, temporal, and structural dimensions. This paper introduces TGNet , a deep learning framework for node ranking in heterogeneous temporal graphs. TGNet utilizes a variant of Recurrent Neural Network to adapt context evolution and extract context features for nodes. It incorporates a novel influence network to dynamically estimate temporal and structural influence among nodes over time. To cope with label sparsity, it integrates graph smoothness constraints as a weak form of supervision. We show that the application of TGNet is feasible for large-scale networks by developing efficient learning and inference algorithms with optimization techniques. Using real-life data, we experimentally verify the effectiveness and efficiency of TGNet techniques. We also show that TGNet yields intuitive explanations for applications such as alert detection and academic impact ranking, as verified by our case study.

Es werden Systeme und Verfahren zum Parsen von Protokollen von beliebigen oder unbekannten Systemen oder Anwendungen durch Erfassen heterogener Protokolle von den beliebigen oder unbekannten Systemen oder Anwendungen; Erzeugen eines Musters fur jede eindeutige Protokollnachricht; Aufbauen eines Musterhierarchiebaums durch Gruppieren von Mustern auf der Grundlage von Ahnlichkeitsmetriken, wobei fur jede Gruppe durch Kombinieren aller Bildungsmuster dieser Gruppe ein Muster erzeugt wird; und Auswahlen einer Menge von Mustern aus dem Musterhierarchiebaum offenbart.

Software-defined networking (SDN) provides fine-grained network control and monitoring that simplifies network management. Unfortunately, upgrading existing enterprise networks, comprised of numerous "legacy" switches, to SDN is often cost-prohibitive. We argue that it is possible to achieve most of the benefits of a fully deployed SDN at a fraction of the cost by strategically replacing only few legacy switches with -- or introducing a few -- new SDN-capable switches in a legacy network, thus creating a hybrid network. We present Magneto, a unified network controller that exerts SDN-like, fine-grained path control over both OpenFlow and legacy switches in hybrid networks. Magneto i) introduces magnet MAC addresses and dynamically updates IP-to-magnet MAC mappings at hosts via gratuitous ARP messages for visibility and routing control; and ii) uses the ability of SDN switches to send "custom" packets into the data plane to manipulate legacy switches into updating forwarding entries with magnet MAC addresses for enhanced routing flexibility. Our evaluation on a lab testbed and through extensive simulations on large enterprise network topologies show that Magneto is able to achieve full control over routing when only 20% of network switches are programmable, with negligible computation and latency overhead.

Network usage accountability is critical in helping operators and customers of multi-tenant data centers deal with concerns such as capacity planning, resource allocation, hotspot detection, link failure detection, and troubleshooting. However, the cost of measurements and instrumentation to achieve flow-level accountability is non-trivial. We propose Polygravity to determine tenant traffic usage via lightweight measurements in multi-tenant data centers. We adopt a tomogravity model widely used in ISP networks, and adapt it to a multi-tenant data center environment. By integrating datacenter-specific domain knowledge, sampling-based partial estimation and gravity-based internal sinks/sources estimation, Polygravity addresses two key challenges for adapting tomogravity to a data center environment: sparse traffic matrices and internal traffic sinks/sources. We conducted extensive evaluation of our approach using realistic data center workloads. Our results show that Polygravity can determine tenant IP flow usage with less than 1% average relative error for tenants with fine-grained domain knowledge. In addition, for tenants with coarse-grained domain knowledge and with partial host-based sampling, Polygravity reduces the relative error of sampling-based estimation by 1/3.

The Nonlinear autoregressive exogenous (NARX) model, which predicts the current value of a time series based upon its previous values as well as the current and past values of multiple driving (exogenous) series, has been studied for decades. Despite the fact that various NARX models have been developed, few of them can capture the long-term temporal dependencies appropriately and select the relevant driving series to make predictions. In this paper, we propose a dual-stage attention-based recurrent neural network (DA-RNN) to address these two issues. In the first stage, we introduce an input attention mechanism to adaptively extract relevant driving series ( a.k.a. , input features) at each time step by referring to the previous encoder hidden state. In the second stage, we use a temporal attention mechanism to select relevant encoder hidden states across all time steps. With this dual-stage attention scheme, our model can not only make predictions effectively, but can also be easily interpreted. Thorough empirical studies based upon the SML 2010 dataset and the NASDAQ 100 Stock dataset demonstrate that the DA-RNN can outperform state-of-the-art methods for time series prediction.

Community detection and role detection in information networks have received wide attention recently, where the former aims to detect the groups of nodes that are closely connected to each other and the latter aims to discover the underlying roles of nodes in the network. Traditional studies treat these two problems as orthogonal issues and propose algorithms for these two tasks separately. In this paper, we propose to integrate communities and roles in a unified model and detect both of them simultaneously for information networks. Intuitively, (1) correctly detecting the communities in a network will lead to the success of detecting roles of nodes, such as opinion leaders and followers in social networks; and (2) correctly identifying the roles of the nodes will lead to a better network modeling and thus a better detection of communities. A novel probabilistic network model, the Mixed Membership Community and Role model (MMCR), is then proposed, which models the latent community and role of each node at the same time, and the probability of links are defined accordingly. By testing our model on synthetic networks and two real-world networks, we demonstrate that our approach leads to better performance for both community detection and role detection. Moreover, our model has a better interpretation for link generation in networks according to the link prediction task.

The stack is a critical memory structure to ensure the correct execution of programs because control flow changes through the data stored in it, such as return addresses and function pointers. Thus the stack has been a popular target by many attacks and exploits like stack smashing attacks and return-oriented programming (ROP). We present a novel system to detect the corruption of the stack layout using a robust stack unwinding technique and detailed stack layouts extracted from the stack unwinding information for exception handling widely available in off-the-shelf binaries. Our evaluation with real-world ROP exploits has demonstrated successful detection of them with performance overhead of only 3.93 % on average transparently without accessing any source code or debugging symbols of a protected binary.

Sequential pattern analysis aims at finding statistically relevant temporal structures where the values are delivered in a sequence. With the growing complexity of real-world dynamic scenarios, more and more symbols are often needed to encode the sequential values. This is so-called “curse of cardinality”, which can impose significant challenges to the design of sequential analysis methods in terms of computational efficiency and practical use. Indeed, given the overwhelming scale and the heterogeneous nature of the sequential data, new visions and strategies are needed to face the challenges. To this end, in this paper, we propose a “temporal skeletonization” approach to proactively reduce the cardinality of the representation for sequences by uncovering significant, hidden temporal structures. The key idea is to summarize the temporal correlations in an undirected graph, and use the “skeleton” of the graph as a higher granularity on which hidden temporal patterns are more likely to be identified. As a consequence, the embedding topology of the graph allows us to translate the rich temporal content into a metric space. This opens up new possibilities to explore, quantify, and visualize sequential data. Our approach has shown to greatly alleviate the curse of cardinality in challenging tasks of sequential pattern mining and clustering. Evaluation on a business-to-business (B2B) marketing application demonstrates that our approach can effectively discover critical buying paths from noisy customer event data.

Intrusion detection system (IDS) is an important part of enterprise security system architecture. In particular, anomaly-based IDS has been widely applied to detect abnormal process behaviors that deviate from the majority. However, such abnormal behavior usually consists of a series of low-level heterogeneous events. The gap between the low-level events and the high-level abnormal behaviors makes it hard to infer which single events are related to the real abnormal activities, especially considering that there are massive "noisy" low-level events happening in between. Hence, the existing work that focus on detecting single entities/events can hardly achieve high detection accuracy. Different from previous work, we design and implement GID, an efficient graph-based intrusion detection technique that can identify abnormal event sequences from a massive heterogeneous process traces with high accuracy. GID first builds a compact graph structure to capture the interactions between different system entities. The suspiciousness or anomaly score of process paths is then measured by leveraging random walk technique to the constructed acyclic directed graph. To eliminate the score bias from the path length, the Box-Cox power transformation based approach is introduced to normalize the anomaly scores so that the scores of paths of different lengths have the same distribution. The efficiency of suspicious path discovery is further improved by the proposed optimization scheme. We fully implement our GID algorithm and deploy it into a real enterprise security system, and it greatly helps detect the advanced threats, and optimize the incident response. Executing GID on system monitoring datasets showing that GID is efficient (about 2 million records per minute) and accurate (higher than 80% in terms of detection rate).

Modern engineering incorporates smart technologies in all aspects of our lives. Smart technologies are generating terabytes of log messages every day to report their status. It is crucial to analyze these log messages and present usable information (e.g. patterns) to administrators, so that they can manage and monitor these technologies. Patterns minimally represent large groups of log messages and enable the administrators to do further analysis, such as anomaly detection and event prediction. Although patterns exist commonly in automated log messages, recognizing them in massive set of log messages from heterogeneous sources without any prior information is a significant undertaking. We propose a method, named LogMine, that extracts high quality patterns for a given set of log messages. Our method is fast, memory efficient, accurate, and scalable. LogMine is implemented in map-reduce framework for distributed platforms to process millions of log messages in seconds. LogMine is a robust method that works for heterogeneous log messages generated in a wide variety of systems. Our method exploits algorithmic techniques to minimize the computational overhead based on the fact that log messages are always automatically generated. We evaluate the performance of LogMine on massive sets of log messages generated in industrial applications. LogMine has successfully generated patterns which are as good as the patterns generated by exact and unscalable method, while achieving a 500× speedup. Finally, we describe three applications of the patterns generated by LogMine in monitoring large scale industrial systems.

Cloud infrastructures provide a rich set of management tasks that operate computing, storage, and networking resources in the cloud. Monitoring the executions of these tasks is crucial for cloud providers to promptly find and understand problems that compromise cloud availability. However, such monitoring is challenging because there are multiple distributed service components involved in the executions. CloudSeer enables effective workflow monitoring. It takes a lightweight non-intrusive approach that purely works on interleaved logs widely existing in cloud infrastructures. CloudSeer first builds an automaton for the workflow of each management task based on normal executions, and then it checks log messages against a set of automata for workflow divergences in a streaming manner. Divergences found during the checking process indicate potential execution problems, which may or may not be accompanied by error log messages. For each potential problem, CloudSeer outputs necessary context information including the affected task automaton and related log messages hinting where the problem occurs to help further diagnosis. Our experiments on OpenStack, a popular open-source cloud infrastructure, show that CloudSeer's efficiency and problem-detection capability are suitable for online monitoring.

Modern world has witnessed a dramatic increase in our ability to collect, transmit and distribute real-time monitoring and surveillance data from large-scale information systems and cyber-physical systems. Detecting system anomalies thus attracts significant amount of interest in many fields such as security, fault management, and industrial optimization. Recently, invariant network has shown to be a powerful way in characterizing complex system behaviours. In the invariant network, a node represents a system component and an edge indicates a stable, significant interaction between two components. Structures and evolutions of the invariance network, in particular the vanishing correlations, can shed important light on locating causal anomalies and performing diagnosis. However, existing approaches to detect causal anomalies with the invariant network often use the percentage of vanishing correlations to rank possible casual components, which have several limitations: 1) fault propagation in the network is ignored; 2) the root casual anomalies may not always be the nodes with a high-percentage of vanishing correlations; 3) temporal patterns of vanishing correlations are not exploited for robust detection. To address these limitations, in this paper we propose a network diffusion based framework to identify significant causal anomalies and rank them. Our approach can effectively model fault propagation over the entire invariant network, and can perform joint inference on both the structural, and the time-evolving broken invariance patterns. As a result, it can locate high-confidence anomalies that are truly responsible for the vanishing correlations, and can compensate for unstructured measurement noise in the system. Extensive experiments on synthetic datasets, bank information system datasets, and coal plant cyber-physical system datasets demonstrate the effectiveness of our approach.