Spacing around overlaid TikZ picture

Question

Input

\documentclass[version=last,paper=A4,parskip=half]{scrartcl}

\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{mlmodern}
\usepackage[american]{babel}
\usepackage[final,babel]{microtype}

\usepackage{lipsum}

\usepackage{tikz}
\usepackage{tcolorbox}

\usetikzlibrary{arrows.meta,calc,fit}
\tcbuselibrary{most}

\begin{document}
\lipsum[1-1]

{%
  \tcbset{%
    enhanced,%
    size=fbox,%
    on line,%
    box align=center,%
    fonttitle=\small,%
    fontupper=\small,%
    fontlower=\small,%
    halign title=center,%
    halign upper=center,%
    halign lower=center,%
  }%
  \begin{tcolorbox}[title=Microservices,remember as=JSON,width=.2\linewidth]
    JSON events\tcblower{}Kafka
  \end{tcolorbox}%
  \hfill%
  \begin{tcolorbox}[title=Databricks,remember as=Spark,width=.2\linewidth]
    Spark\tcblower{}EC2 \& EBS
  \end{tcolorbox}%
  \hfill%
  \begin{minipage}{.2\linewidth}
    \begin{tcolorbox}[remember as=Oracle]
      Oracle
    \end{tcolorbox}%
    \\%
    \begin{tcolorbox}[remember as=Delta]
      Delta Lake\tcblower{}S3
    \end{tcolorbox}
  \end{minipage}%
  \hfill%
  \begin{minipage}{.15\linewidth}
    \begin{tcolorbox}[remember as=Exasol]
      Exasol
    \end{tcolorbox}%
    \\%
    \begin{tcolorbox}[remember as=Presto]
      Presto
    \end{tcolorbox}%
  \end{minipage}%
  \begin{tikzpicture}[%
    overlay,%
    remember picture,%
    >=Stealth,%
    shorten >=1pt,%
    shorten <=1pt,%
    surround/.style 2 args={%
      draw,%
      rectangle,%
      thick,%
      dotted,%
      fit=#1,%
      inner sep=8pt,%
      label={[align=center,scale=0.75]#2},%
    },%
    ]

    \coordinate (Spark-SSE)  at ($(Spark.south)!0.5!(Spark.south east)$);
    \coordinate (Spark-NNE)  at ($(Spark.north)!0.5!(Spark.north east)$);
    \coordinate (Delta-SSW)  at ($(Delta.south)!0.5!(Delta.south west)$);
    \coordinate (Exasol-NNW) at ($(Exasol.north)!0.5!(Exasol.north west)$);

    \path[->]
    (JSON)      edge                                       (Spark)
    (Spark)     edge                                       (Oracle)
    (Oracle)    edge                                       (Exasol)
    (Spark)     edge                                       (Delta)
    (Delta)     edge[<->]                                  (Presto)
    (Delta-SSW) edge[out=-150,in=-30]
                node[midway,below,scale=0.75] {SNS \& SQS} (Spark-SSE)
    (Spark-NNE) edge[out=30,in=150]                        (Exasol-NNW);

    \node[surround={(Spark)}{Airflow}]                          (Scheduling) {};
    \node[surround={(Exasol)(Presto)}{Superset\\MicroStrategy}] (Reporting)  {};
  \end{tikzpicture}%
}

\lipsum[2-2]
\end{document}

Output

Click to view output with no spacing around overlaid TikZ picture

Question

How can I automatically add spacing around the overlaid TikZ picture so that its contents do not go over the surrounding text?

Answer 1

I would draw you image as pure TikZ picture and enclose it in a center environment. In the picture are not used remember picture and overlay options, which cause your problem. In comparison to your solution with tcolorbox code is simpler, more clear and shorter:

(red lines are text borders)

\documentclass[version=last,paper=A4,parskip=half]{scrartcl}
%--------------- show page layout. don't use in a real document!
\usepackage{showframe}
\renewcommand\ShowFrameLinethickness{0.15pt}
\renewcommand*\ShowFrameColor{\color{red}}
%
\usepackage{lipsum}                             % for dummy text
%---------------------------------------------------------------%

\usepackage{tikz}
\usetikzlibrary{arrows.meta,
                fit,
                positioning,
                quotes,
                shapes.multipart}

\begin{document}
\lipsum[11]

\begin{center}
  \begin{tikzpicture}[
  node distance = 1mm and 0.05\linewidth,
every edge/.append style = {draw, -Stealth},
every label/.append style = {align=center},
FIT/.style = {draw, densely dashed, rounded corners=2pt,
              fit=#1, node contents={} },
MPV/.style = {
        rectangle split parts=3, 
        shape=rectangle split, 
        rectangle split draw splits=false,
        rectangle split part fill={black, gray!30},
        draw, rounded corners=1pt,
        inner sep=1mm, text width=0.2\linewidth, align=center,
        },
  N/.style = {draw, rounded corners=1pt, fill=gray!30,
        text width=0.18\linewidth, align=center}
                        ]
\node (n1)  [MPV] {%
        \nodepart{one}   \textcolor{white}{\textbf{Microservices}}
        \nodepart{two}   JSOM events
        \nodepart{three} Kafka};
        \draw[dashed]   (n1.two split west) -- (n1.two split east);
\node (n2)  [MPV, right=of n1] {%
        \nodepart{one}   \textcolor{white}{\textbf{Databricks}}
        \nodepart{two}   Spark
        \nodepart{three} EC2 \& EBS};
        \draw[dashed]   (n2.two split west) -- (n2.two split east);
    \node[FIT=(n2)];
\node (n3a) [N, right=of n2.one east] 
        {Oracle};
\node (n3b) [N,below=of n3a] 
        {Exasol\\S3};
        \draw[dashed]   (n3b.west) -- (n3b.east);
\node (n4a) [N, right=of n3a.south east]
        {Oracle};
\node (n4b) [N, below=of n4a]
        {Presto};
        \draw[dashed]   (n3b.west) -- (n3b.east);
    \node[FIT=(n4a) (n4b), label={Superset\\MicroStrategy}];
% connections
\draw   (n1) edge (n2)
        (n2) edge (n3a)
        (n2) edge (n3b)
        (n3a)   edge    (n4a);
\draw[Stealth-Stealth]  (n4b)   edge    (n3b);
%
\draw   (n2.75)    edge[bend left] (n4a)
        (n3b)   edge[bend left=30,"SNS \& SQS"] (n2.285);
%
\draw[-Stealth] (n1) -- (n2);
   \end{tikzpicture}                 
\end{center}
\lipsum[12]
\end{document}